diff --git a/tests/playwright/e2e/appstore/admin-settings-apps.spec.ts b/tests/playwright/e2e/appstore/admin-settings-apps.spec.ts
index e00b5df646f96..9ed2e73c7b4ae 100644
--- a/tests/playwright/e2e/appstore/admin-settings-apps.spec.ts
+++ b/tests/playwright/e2e/appstore/admin-settings-apps.spec.ts
@@ -22,6 +22,12 @@ test.describe('Settings: App management', () => {
 		await appstorePage.appsTable().waitFor({ state: 'visible', timeout: 10000 })
 	})
 
+	test.afterAll(async () => {
+		// Leave the apps the tests toggle in the state the other suites expect
+		await runOcc(['app:disable', 'testing'], { failOnError: false })
+		await runOcc(['app:enable', 'updatenotification'], { failOnError: false })
+	})
+
 	test('Can enable an installed app', async ({ page, appstorePage }) => {
 		// Intercept the enable app request
 		const enableRequest = page.waitForResponse((response) => response.url().includes('/ocs/v2.php/apps/appstore/api/v1/apps/enable'))
diff --git a/tests/playwright/e2e/files/files-renaming.spec.ts b/tests/playwright/e2e/files/files-renaming.spec.ts
index e7260381757db..93e8436f23fd9 100644
--- a/tests/playwright/e2e/files/files-renaming.spec.ts
+++ b/tests/playwright/e2e/files/files-renaming.spec.ts
@@ -40,9 +40,11 @@ test.describe('Files: Rename nodes', () => {
 		const input = filesListPage.getRenameInputForFile('file.txt')
 		await expect(input).toBeVisible()
 
-		const { selectionStart, selectionEnd } = await input.evaluate((el) => ({ selectionStart: (el as HTMLInputElement).selectionStart, selectionEnd: (el as HTMLInputElement).selectionEnd }))
-		expect(selectionStart).toBe(0)
-		expect(selectionEnd).toBe('file'.length)
+		// The selection is applied after the input is shown
+		await expect.poll(() => input.evaluate((el) => {
+			const { selectionStart, selectionEnd } = el as HTMLInputElement
+			return { selectionStart, selectionEnd }
+		})).toEqual({ selectionStart: 0, selectionEnd: 'file'.length })
 	})
 
 	test('shows validation error on invalid filename', async ({ filesListPage }) => {
diff --git a/tests/playwright/e2e/files_trashbin/files.spec.ts b/tests/playwright/e2e/files_trashbin/files.spec.ts
index 7a21659aa354a..78f0f55d0e9b1 100644
--- a/tests/playwright/e2e/files_trashbin/files.spec.ts
+++ b/tests/playwright/e2e/files_trashbin/files.spec.ts
@@ -9,7 +9,7 @@ import type { TrashbinListPage } from '../../support/sections/TrashbinListPage.t
 import { readFile } from 'node:fs/promises'
 import { expect, test } from '../../support/fixtures/files-trashbin-page.ts'
 import { mkdir, rm, uploadContent } from '../../support/utils/dav.ts'
-import { createShare, ShareType } from '../../support/utils/sharing.ts'
+import { createShare, ShareType, waitForShare } from '../../support/utils/sharing.ts'
 import { setUserDisplayName } from '../../support/utils/users.ts'
 
 test.describe('files_trashbin: download files', () => {
@@ -71,6 +71,7 @@ test.describe('files_trashbin: file row', () => {
 
 		const fileId = Number(await uploadContent(aliceRequest, user, '<content>', 'text/plain', '/Shared/test-file.txt'))
 		// Bob (the sharee) deletes the file from his view of the shared folder
+		await waitForShare(bobRequest, bob, 'Shared', 'test-file.txt')
 		await rm(bobRequest, bob, '/Shared/test-file.txt')
 
 		await filesListPage.open('trashbin')
diff --git a/tests/playwright/e2e/settings/personal-info.spec.ts b/tests/playwright/e2e/settings/personal-info.spec.ts
index cef090218b291..96caa264eeded 100644
--- a/tests/playwright/e2e/settings/personal-info.spec.ts
+++ b/tests/playwright/e2e/settings/personal-info.spec.ts
@@ -12,16 +12,10 @@ test.describe('Settings: Change personal information', () => {
 	test.beforeAll(async () => {
 		// Prevent the Fediverse section from making outbound HTTP requests
 		await runOcc(['config:system:set', 'has_internet_connection', '--type', 'bool', '--value', 'false'])
-		// Let each user choose their own language and locale
-		await runOcc(['config:system:delete', 'force_language'])
-		await runOcc(['config:system:delete', 'force_locale'])
 	})
 
 	test.afterAll(async () => {
 		await runOcc(['config:system:delete', 'has_internet_connection'])
-		// Restore English defaults so other test suites are unaffected
-		await runOcc(['config:system:set', 'force_language', '--value', 'en'])
-		await runOcc(['config:system:set', 'force_locale', '--value', 'en_US'])
 	})
 
 	// ── Profile ───────────────────────────────────────────────────────────────
@@ -36,7 +30,7 @@ test.describe('Settings: Change personal information', () => {
 		await profileContactPage.setProfileEnabled(false)
 
 		// Profile is disabled: the public profile page shows a "not found" heading
-		await page.goto(`/u/${user.userId}`, { waitUntil: 'networkidle' })
+		await page.goto(`/u/${user.userId}`)
 		await expect(page.getByRole('heading', { name: /Profile not found/i })).toBeVisible()
 
 		// Re-enable the profile
@@ -343,13 +337,22 @@ test.describe('Settings: Change personal information', () => {
 	// ── Language & locale ─────────────────────────────────────────────────────
 
 	test.describe('Language & locale', () => {
-		test.beforeEach(async () => {
-			// The section is read-only while a language or locale is enforced, and a
-			// parallel worker may have restored the defaults of this suite already
+		// The section is read-only while a language or locale is enforced. Lifting
+		// the instance-wide enforcement must happen in a single worker, otherwise
+		// one worker's cleanup re-enforces it while another is still testing.
+		test.describe.configure({ mode: 'serial' })
+
+		test.beforeAll(async () => {
 			await runOcc(['config:system:delete', 'force_language'])
 			await runOcc(['config:system:delete', 'force_locale'])
 		})
 
+		test.afterAll(async () => {
+			// Restore the test server's English defaults for the other suites
+			await runOcc(['config:system:set', 'force_language', '--value', 'en'])
+			await runOcc(['config:system:set', 'force_locale', '--value', 'en_US'])
+		})
+
 		test('can change language', async ({ page, languageLocalePage }) => {
 			await languageLocalePage.open()
 
@@ -365,10 +368,10 @@ test.describe('Settings: Change personal information', () => {
 			// The example is rendered in the active locale, US English by default
 			await expect(languageLocalePage.localeExample()).toContainText(/Example: \d{2}\/\d{2}\/\d{4}/)
 
-			await languageLocalePage.selectLocale('German (Germany)', 'German')
-
 			// Locale change triggers a full page reload
-			await page.waitForLoadState('networkidle')
+			const reloaded = page.waitForEvent('load')
+			await languageLocalePage.selectLocale('German (Germany)', 'German')
+			await reloaded
 			await languageLocalePage.expectSelected(languageLocalePage.localeSelect(), 'German (Germany)')
 			// The example now uses the German date format
 			await expect(languageLocalePage.localeExample()).toContainText(/Example: \d{2}\.\d{2}\.\d{4}/)
diff --git a/tests/playwright/e2e/systemtags/admin-settings-restrictions.spec.ts b/tests/playwright/e2e/systemtags/admin-settings-restrictions.spec.ts
index 0cc1eea013b3b..6f396df965430 100644
--- a/tests/playwright/e2e/systemtags/admin-settings-restrictions.spec.ts
+++ b/tests/playwright/e2e/systemtags/admin-settings-restrictions.spec.ts
@@ -7,11 +7,10 @@ import { runOcc } from '@nextcloud/e2e-test-server'
 import { expect } from '@playwright/test'
 import { test } from '../../support/fixtures/systemtags-files-page.ts'
 import { uploadContent } from '../../support/utils/dav.ts'
-import { clearTags, createTag } from '../../support/utils/systemtags.ts'
+import { createTag } from '../../support/utils/systemtags.ts'
 
 test.beforeAll(async () => await runOcc(['config:app:set', 'systemtags', 'restrict_creation_to_admin', '--value', '1']))
 test.afterAll(async () => await runOcc(['config:app:delete', 'systemtags', 'restrict_creation_to_admin']))
-test.afterAll(async () => await clearTags())
 
 test.beforeEach(async ({ filesListPage, page, user }) => {
 	await uploadContent(page.request, user, Buffer.alloc(0), 'text/plain', '/file1.txt')
@@ -19,8 +18,8 @@ test.beforeEach(async ({ filesListPage, page, user }) => {
 	await filesListPage.open()
 })
 
-test('Cannot create tag if restriction is in place', async ({ filesListPage }) => {
-	const tag = crypto.randomUUID()
+test('Cannot create tag if restriction is in place', async ({ filesListPage, tagName }) => {
+	const tag = tagName()
 	await createTag(tag, 'public')
 
 	await filesListPage.expectInlineTagsForFile('file1.txt', [])
diff --git a/tests/playwright/e2e/systemtags/admin-settings.spec.ts b/tests/playwright/e2e/systemtags/admin-settings.spec.ts
index cf796fe127002..29d4382f781aa 100644
--- a/tests/playwright/e2e/systemtags/admin-settings.spec.ts
+++ b/tests/playwright/e2e/systemtags/admin-settings.spec.ts
@@ -4,21 +4,19 @@
  */
 
 import { expect } from '@playwright/test'
-import { test } from '../../support/fixtures/admin-session.ts'
-import { createTag, deleteTag, listTags } from '../../support/utils/systemtags.ts'
+import { test as adminTest } from '../../support/fixtures/admin-session.ts'
+import { createTag, tagNameFixture } from '../../support/utils/systemtags.ts'
 
-const tagName = 'foo'
-const updatedTagName = 'bar'
+const test = adminTest.extend<{ tagName: () => string }>({
+	tagName: tagNameFixture,
+})
 
-test.describe('System tags admin settings', () => {
-	test.beforeEach(async () => {
-		const tags = await listTags()
-		for (const tag of tags) {
-			await deleteTag(tag.id)
-		}
-	})
+// NcEllipsisedOption splits names of 10+ chars across two spans, which breaks the
+// option's accessible name, so options are matched on their text content instead.
 
-	test('Can create a tag', async ({ page }) => {
+test.describe('System tags admin settings', () => {
+	test('Can create a tag', async ({ page, tagName: generateTagName }) => {
+		const tagName = generateTagName()
 		await page.goto('settings/admin/server')
 
 		// Scroll the collaborative tags section into view — the admin settings page is long
@@ -35,10 +33,12 @@ test.describe('System tags admin settings', () => {
 
 		// The form resets after creation — verify the tag now appears in the selection dropdown
 		await page.getByRole('combobox', { name: 'Search for a tag to edit' }).click()
-		await expect(page.getByRole('option', { name: tagName })).toBeVisible()
+		await expect(page.getByRole('option').filter({ hasText: tagName })).toBeVisible()
 	})
 
-	test('Can update a tag', async ({ page }) => {
+	test('Can update a tag', async ({ page, tagName: generateTagName }) => {
+		const tagName = generateTagName()
+		const updatedTagName = generateTagName()
 		await createTag(tagName)
 
 		await page.goto('settings/admin/server')
@@ -46,7 +46,7 @@ test.describe('System tags admin settings', () => {
 
 		// Select the tag to edit
 		await page.getByRole('combobox', { name: 'Search for a tag to edit' }).click()
-		await page.getByRole('option', { name: tagName }).click()
+		await page.getByRole('option').filter({ hasText: tagName }).click()
 
 		// Verify the form reflects the selected tag
 		await expect(page.getByLabel('Tag name')).toHaveValue(tagName)
@@ -65,13 +65,11 @@ test.describe('System tags admin settings', () => {
 		expect((await updateResponse).status()).toBe(207)
 
 		await page.getByRole('combobox', { name: 'Search for a tag to edit' }).click()
-		// NcEllipsisedOption splits names ≥ 10 chars across two spans, breaking the accessible name.
-		// "bar (invisible)" (15 chars) splits at position 8 → accessible name "bar (inv isible)".
-		// Use filter({ hasText }) to match on text content instead of the exact accessible name.
 		await expect(page.getByRole('option').filter({ hasText: updatedTagName })).toBeVisible()
 	})
 
-	test('Can delete a tag', async ({ page }) => {
+	test('Can delete a tag', async ({ page, tagName: generateTagName }) => {
+		const tagName = generateTagName()
 		await createTag(tagName)
 
 		await page.goto('settings/admin/server')
diff --git a/tests/playwright/e2e/systemtags/files-bulk-action.spec.ts b/tests/playwright/e2e/systemtags/files-bulk-action.spec.ts
index 7614d8c2c9dfb..9749bf3610fa2 100644
--- a/tests/playwright/e2e/systemtags/files-bulk-action.spec.ts
+++ b/tests/playwright/e2e/systemtags/files-bulk-action.spec.ts
@@ -5,7 +5,7 @@
 
 import { test as baseTest } from '../../support/fixtures/systemtags-files-page.ts'
 import { uploadContent } from '../../support/utils/dav.ts'
-import { assignTagsToFile, clearTags, createTag } from '../../support/utils/systemtags.ts'
+import { assignTagsToFile, createTag } from '../../support/utils/systemtags.ts'
 
 // Extends the base fixture with per-test file IDs so tests in parallel each get
 // their own isolated file IDs rather than sharing module-level mutable state.
@@ -19,11 +19,9 @@ const test = baseTest.extend<{ fileIds: [string, string] }>({
 })
 
 test.describe('Systemtags: Files bulk action', () => {
-	test.afterAll(async () => await clearTags())
-
 	// eslint-disable-next-line @typescript-eslint/no-unused-vars -- Needed to execute the upload by PlayWright
-	test('Can assign tag to selection', async ({ filesListPage, fileIds }) => {
-		const tag = crypto.randomUUID()
+	test('Can assign tag to selection', async ({ filesListPage, fileIds, tagName }) => {
+		const tag = tagName()
 
 		await filesListPage.expectInlineTagsForFile('file1.txt', [])
 		await filesListPage.expectInlineTagsForFile('file2.txt', [])
@@ -39,9 +37,9 @@ test.describe('Systemtags: Files bulk action', () => {
 		await filesListPage.expectInlineTagsForFile('file2.txt', [tag])
 	})
 
-	test('Can assign multiple tags to selection', async ({ filesListPage }) => {
-		const tag1 = crypto.randomUUID()
-		const tag2 = crypto.randomUUID()
+	test('Can assign multiple tags to selection', async ({ filesListPage, tagName }) => {
+		const tag1 = tagName()
+		const tag2 = tagName()
 
 		await filesListPage.expectInlineTagsForFile('file1.txt', [])
 		await filesListPage.expectInlineTagsForFile('file2.txt', [])
@@ -58,9 +56,9 @@ test.describe('Systemtags: Files bulk action', () => {
 		await filesListPage.expectInlineTagsForFile('file2.txt', [tag1, tag2])
 	})
 
-	test('Can remove tag from selection', async ({ filesListPage, page, fileIds }) => {
-		const tag1 = crypto.randomUUID()
-		const tag2 = crypto.randomUUID()
+	test('Can remove tag from selection', async ({ filesListPage, page, fileIds, tagName }) => {
+		const tag1 = tagName()
+		const tag2 = tagName()
 		await assignTagsToFile(fileIds[0], [tag1, tag2])
 		await assignTagsToFile(fileIds[1], [tag1, tag2])
 		await page.reload()
@@ -79,10 +77,10 @@ test.describe('Systemtags: Files bulk action', () => {
 		await filesListPage.expectInlineTagsForFile('file2.txt', [tag1])
 	})
 
-	test('Can remove multiple tags from selection', async ({ filesListPage, page, fileIds }) => {
-		const tag1 = crypto.randomUUID()
-		const tag2 = crypto.randomUUID()
-		const tag3 = crypto.randomUUID()
+	test('Can remove multiple tags from selection', async ({ filesListPage, page, fileIds, tagName }) => {
+		const tag1 = tagName()
+		const tag2 = tagName()
+		const tag3 = tagName()
 		await assignTagsToFile(fileIds[0], [tag1, tag2, tag3])
 		await assignTagsToFile(fileIds[1], [tag1, tag2, tag3])
 		await page.reload()
@@ -102,10 +100,10 @@ test.describe('Systemtags: Files bulk action', () => {
 		await filesListPage.expectInlineTagsForFile('file2.txt', [tag1])
 	})
 
-	test('Can assign and remove multiple tags', async ({ filesListPage, page, fileIds }) => {
-		const tag1 = crypto.randomUUID()
-		const tag2 = crypto.randomUUID()
-		const tag3 = crypto.randomUUID()
+	test('Can assign and remove multiple tags', async ({ filesListPage, page, fileIds, tagName }) => {
+		const tag1 = tagName()
+		const tag2 = tagName()
+		const tag3 = tagName()
 		await assignTagsToFile(fileIds[0], [tag1, tag2])
 		await assignTagsToFile(fileIds[1], [tag1, tag2])
 		await page.reload()
@@ -125,8 +123,8 @@ test.describe('Systemtags: Files bulk action', () => {
 		await filesListPage.expectInlineTagsForFile('file2.txt', [tag1, tag3])
 	})
 
-	test('Can search for tags with insensitive case', async ({ filesListPage }) => {
-		const tag = crypto.randomUUID().toLowerCase()
+	test('Can search for tags with insensitive case', async ({ filesListPage, tagName }) => {
+		const tag = tagName()
 		await createTag(tag, 'public')
 
 		await filesListPage.expectInlineTagsForFile('file1.txt', [])
diff --git a/tests/playwright/e2e/systemtags/files-inline-action.spec.ts b/tests/playwright/e2e/systemtags/files-inline-action.spec.ts
index a2383af3f15e7..2bb647e2cbe1a 100644
--- a/tests/playwright/e2e/systemtags/files-inline-action.spec.ts
+++ b/tests/playwright/e2e/systemtags/files-inline-action.spec.ts
@@ -5,18 +5,15 @@
 
 import { expect, test } from '../../support/fixtures/systemtags-files-page.ts'
 import { uploadContent } from '../../support/utils/dav.ts'
-import { clearTags } from '../../support/utils/systemtags.ts'
 
 test.describe('Systemtags: Files integration', () => {
-	test.afterAll(async () => await clearTags())
-
 	test.beforeEach(async ({ page, user, filesListPage }) => {
 		await uploadContent(page.request, user, Buffer.alloc(0), 'text/plain', '/file.txt')
 		await filesListPage.open()
 	})
 
-	test('See first assigned tag in the file list', async ({ page, filesListPage }) => {
-		const tag = crypto.randomUUID()
+	test('See first assigned tag in the file list', async ({ page, filesListPage, tagName }) => {
+		const tag = tagName()
 
 		await filesListPage.openTagPickerForFile('file.txt')
 		await filesListPage.createNewTagInPicker(tag)
@@ -29,9 +26,9 @@ test.describe('Systemtags: Files integration', () => {
 		await expect(tagList.getByRole('listitem')).toContainText(tag)
 	})
 
-	test('See two assigned tags are also shown in the file list', async ({ page, filesListPage }) => {
-		const tag1 = crypto.randomUUID()
-		const tag2 = crypto.randomUUID()
+	test('See two assigned tags are also shown in the file list', async ({ page, filesListPage, tagName }) => {
+		const tag1 = tagName()
+		const tag2 = tagName()
 
 		await filesListPage.openTagPickerForFile('file.txt')
 		await filesListPage.createNewTagInPicker(tag1)
@@ -46,10 +43,10 @@ test.describe('Systemtags: Files integration', () => {
 		await expect(tagList).toContainText(tag2)
 	})
 
-	test('See three assigned tags result in overflow entry', async ({ page, filesListPage }) => {
-		const tag1 = crypto.randomUUID()
-		const tag2 = crypto.randomUUID()
-		const tag3 = crypto.randomUUID()
+	test('See three assigned tags result in overflow entry', async ({ page, filesListPage, tagName }) => {
+		const tag1 = tagName()
+		const tag2 = tagName()
+		const tag3 = tagName()
 
 		await filesListPage.openTagPickerForFile('file.txt')
 		await filesListPage.createNewTagInPicker(tag1)
diff --git a/tests/playwright/e2e/systemtags/files-sidebar.spec.ts b/tests/playwright/e2e/systemtags/files-sidebar.spec.ts
index 3decfaf866d0d..0ae72e4448e4e 100644
--- a/tests/playwright/e2e/systemtags/files-sidebar.spec.ts
+++ b/tests/playwright/e2e/systemtags/files-sidebar.spec.ts
@@ -5,18 +5,15 @@
 
 import { expect, test } from '../../support/fixtures/systemtags-files-page.ts'
 import { uploadContent } from '../../support/utils/dav.ts'
-import { clearTags } from '../../support/utils/systemtags.ts'
 
 test.describe('Systemtags: Files sidebar integration', () => {
-	test.afterAll(async () => await clearTags())
-
 	test.beforeEach(async ({ page, user, filesListPage }) => {
 		await uploadContent(page.request, user, Buffer.alloc(0), 'text/plain', '/file.txt')
 		await filesListPage.open()
 	})
 
-	test('Can assign tags using the sidebar', async ({ filesListPage, filesSidebar }) => {
-		const tag = crypto.randomUUID()
+	test('Can assign tags using the sidebar', async ({ filesListPage, filesSidebar, tagName }) => {
+		const tag = tagName()
 
 		await expect(filesListPage.getRowForFile('file.txt')).toBeVisible()
 
diff --git a/tests/playwright/e2e/systemtags/files-view.spec.ts b/tests/playwright/e2e/systemtags/files-view.spec.ts
index dc2fe681c8da3..9a686b4517fc5 100644
--- a/tests/playwright/e2e/systemtags/files-view.spec.ts
+++ b/tests/playwright/e2e/systemtags/files-view.spec.ts
@@ -5,19 +5,16 @@
 
 import { expect, test } from '../../support/fixtures/systemtags-files-page.ts'
 import { mkdir, uploadContent } from '../../support/utils/dav.ts'
-import { clearTags } from '../../support/utils/systemtags.ts'
 
 test.describe('Systemtags: Files view', () => {
-	test.afterAll(async () => await clearTags())
-
 	test.beforeEach(async ({ page, user, filesListPage }) => {
 		await mkdir(page.request, user, '/folder')
 		await uploadContent(page.request, user, Buffer.alloc(0), 'text/plain', '/file.txt')
 		await filesListPage.open()
 	})
 
-	test('See first assigned tag in the file list', async ({ page, filesListPage }) => {
-		const tag = crypto.randomUUID()
+	test('See first assigned tag in the file list', async ({ page, filesListPage, tagName }) => {
+		const tag = tagName()
 
 		await expect(filesListPage.getRowForFile('folder')).toBeVisible()
 		await expect(filesListPage.getRowForFile('file.txt')).toBeVisible()
diff --git a/tests/playwright/support/fixtures/admin-session.ts b/tests/playwright/support/fixtures/admin-session.ts
index 5f3f577c68991..eec169e2cf4b0 100644
--- a/tests/playwright/support/fixtures/admin-session.ts
+++ b/tests/playwright/support/fixtures/admin-session.ts
@@ -7,18 +7,13 @@ import { User } from '@nextcloud/e2e-test-server'
 import { login } from '@nextcloud/e2e-test-server/playwright'
 import { test as baseTest } from '@playwright/test'
 import { installPasswordConfirmationHandler } from '../utils/password-confirmation.ts'
+import { retryWithBackoff } from '../utils/retry.ts'
 
 const admin = new User('admin', 'admin')
 
 export const test = baseTest.extend({
 	page: async ({ page, context }, use) => {
-		try {
-			await login(context.request, admin)
-		} catch (error) {
-			console.info('Failed to authenticate as admin, retrying', error)
-			await new Promise((resolve) => setTimeout(resolve, 800))
-			await login(context.request, admin)
-		}
+		await retryWithBackoff('Authenticating as admin', () => login(context.request, admin))
 		await installPasswordConfirmationHandler(page, admin.password)
 		await use(page)
 	},
diff --git a/tests/playwright/support/fixtures/random-user-session.ts b/tests/playwright/support/fixtures/random-user-session.ts
index daa4636def12a..b3718804c0703 100644
--- a/tests/playwright/support/fixtures/random-user-session.ts
+++ b/tests/playwright/support/fixtures/random-user-session.ts
@@ -5,6 +5,7 @@
 
 import { login } from '@nextcloud/e2e-test-server/playwright'
 import { installPasswordConfirmationHandler } from '../utils/password-confirmation.ts'
+import { retryWithBackoff } from '../utils/retry.ts'
 import { test as randomUserTest } from './random-user.ts'
 
 /**
@@ -14,13 +15,7 @@ import { test as randomUserTest } from './random-user.ts'
 export const test = randomUserTest.extend({
 	page: async ({ browser, user }, use) => {
 		const page = await browser.newPage()
-		try {
-			await login(page.request, user)
-		} catch (error) {
-			console.info('Failed to authenticate as random user, retrying', error)
-			await new Promise((resolve) => setTimeout(resolve, 800))
-			await login(page.request, user)
-		}
+		await retryWithBackoff('Authenticating as random user', () => login(page.request, user))
 		await installPasswordConfirmationHandler(page, user.password)
 		await use(page)
 	},
diff --git a/tests/playwright/support/fixtures/random-user.ts b/tests/playwright/support/fixtures/random-user.ts
index ebef3792f4934..c0e68c94d7ebc 100644
--- a/tests/playwright/support/fixtures/random-user.ts
+++ b/tests/playwright/support/fixtures/random-user.ts
@@ -8,6 +8,7 @@ import type { User } from '@nextcloud/e2e-test-server'
 import { runOcc } from '@nextcloud/e2e-test-server/docker'
 import { createRandomUser } from '@nextcloud/e2e-test-server/playwright'
 import { test as baseTest } from '@playwright/test'
+import { retryWithBackoff } from '../utils/retry.ts'
 
 /**
  * Extends the base test with a freshly-created random `user`.
@@ -15,14 +16,7 @@ import { test as baseTest } from '@playwright/test'
  */
 export const test = baseTest.extend<{ user: User }>({
 	user: async ({}, use) => {
-		let user: User
-		try {
-			user = await createRandomUser()
-		} catch {
-			// Retry once on transient failure
-			await new Promise((resolve) => setTimeout(resolve, 800))
-			user = await createRandomUser()
-		}
+		const user = await retryWithBackoff('Creating a random user', () => createRandomUser())
 		await use(user)
 		await runOcc(['user:delete', user.userId], { failOnError: false })
 	},
diff --git a/tests/playwright/support/fixtures/systemtags-files-page.ts b/tests/playwright/support/fixtures/systemtags-files-page.ts
index 894ea1c029989..543fe6906d7ff 100644
--- a/tests/playwright/support/fixtures/systemtags-files-page.ts
+++ b/tests/playwright/support/fixtures/systemtags-files-page.ts
@@ -4,21 +4,25 @@
  */
 
 import { SystemTagsFilesListPage } from '../sections/SystemTagsFilesListPage.ts'
+import { tagNameFixture } from '../utils/systemtags.ts'
 import { test as filesTest } from './files-page.ts'
 
 type SystemTagsFixtures = {
 	filesListPage: SystemTagsFilesListPage
+	tagName: () => string
 }
 
 /**
  * Extends the base files-page fixture by replacing `filesListPage` with a
  * {@link SystemTagsFilesListPage}, which adds SystemTagPicker actions and
- * inline-tags assertion helpers on top of the standard file list interactions.
+ * inline-tags assertion helpers on top of the standard file list interactions,
+ * and provides `tagName` to generate tag names that are cleaned up after the test.
  */
 export const test = filesTest.extend<SystemTagsFixtures>({
 	filesListPage: async ({ page }, use) => {
 		await use(new SystemTagsFilesListPage(page))
 	},
+	tagName: tagNameFixture,
 })
 
 export { expect } from '../matchers.ts'
diff --git a/tests/playwright/support/fixtures/transfer-ownership-page.ts b/tests/playwright/support/fixtures/transfer-ownership-page.ts
index 6db18102daf0d..62efd49b71f4e 100644
--- a/tests/playwright/support/fixtures/transfer-ownership-page.ts
+++ b/tests/playwright/support/fixtures/transfer-ownership-page.ts
@@ -10,6 +10,7 @@ import { runOcc } from '@nextcloud/e2e-test-server/docker'
 import { createRandomUser, login } from '@nextcloud/e2e-test-server/playwright'
 import { FilesListPage } from '../sections/FilesListPage.ts'
 import { TransferOwnershipPage } from '../sections/TransferOwnershipPage.ts'
+import { retryWithBackoff } from '../utils/retry.ts'
 import { test as filesTest } from './files-page.ts'
 
 type TransferOwnershipFixtures = {
@@ -36,14 +37,7 @@ type TransferOwnershipFixtures = {
  */
 export const test = filesTest.extend<TransferOwnershipFixtures>({
 	recipient: async ({}, use) => {
-		let recipient: User
-		try {
-			recipient = await createRandomUser()
-		} catch {
-			// Retry once on transient failure, as the `user` fixture does
-			await new Promise((resolve) => setTimeout(resolve, 800))
-			recipient = await createRandomUser()
-		}
+		const recipient = await retryWithBackoff('Creating the recipient', () => createRandomUser())
 		await use(recipient)
 		await runOcc(['user:delete', recipient.userId], { failOnError: false })
 	},
@@ -62,14 +56,7 @@ export const test = filesTest.extend<TransferOwnershipFixtures>({
 	recipientPage: async ({ browser, recipient }, use) => {
 		const context = await browser.newContext()
 		const recipientPage = await context.newPage()
-		try {
-			await login(recipientPage.request, recipient)
-		} catch (error) {
-			// Same transient failure the session of `user` is retried for
-			console.info('Failed to authenticate as recipient, retrying', error)
-			await new Promise((resolve) => setTimeout(resolve, 800))
-			await login(recipientPage.request, recipient)
-		}
+		await retryWithBackoff('Authenticating as recipient', () => login(recipientPage.request, recipient))
 		await use(recipientPage)
 		await context.close()
 	},
diff --git a/tests/playwright/support/sections/AppstorePage.ts b/tests/playwright/support/sections/AppstorePage.ts
index e936cb998ef21..6836a03815236 100644
--- a/tests/playwright/support/sections/AppstorePage.ts
+++ b/tests/playwright/support/sections/AppstorePage.ts
@@ -56,10 +56,14 @@ export class AppstorePage {
 	}
 
 	/**
-	 * Gets a specific app row by app name
+	 * Gets a specific app row by app name. The name is matched exactly, so
+	 * "Files" does not also match "Files sharing".
 	 */
 	appRow(appName: string): Locator {
-		return this.appsTable().locator('tr').filter({ hasText: appName }).first()
+		// The details link is named "<app name> (Show details)"
+		const escapedName = appName.replace(/[.*+?^${}()|[\]\\]/g, '\\$&')
+		const detailsLink = this.page.getByRole('link', { name: new RegExp(`^${escapedName} \\(`) })
+		return this.appsTable().getByRole('row').filter({ has: detailsLink })
 	}
 
 	/**
diff --git a/tests/playwright/support/sections/ContactsMenuPage.ts b/tests/playwright/support/sections/ContactsMenuPage.ts
index f13856636f7ed..8062b77396498 100644
--- a/tests/playwright/support/sections/ContactsMenuPage.ts
+++ b/tests/playwright/support/sections/ContactsMenuPage.ts
@@ -65,6 +65,10 @@ export class ContactsMenuPage {
 	 * a network request always follows a fill().
 	 */
 	async search(query: string): Promise<void> {
+		const searched = this.page.waitForResponse((r) => r.url().includes('/contactsmenu/contacts')
+			&& r.request().method() === 'POST'
+			&& r.request().postDataJSON()?.filter === query)
 		await this.page.getByRole('searchbox', { name: 'Search contacts' }).fill(query)
+		await searched
 	}
 }
diff --git a/tests/playwright/support/sections/FilesListPage.ts b/tests/playwright/support/sections/FilesListPage.ts
index 0e21a744e908d..003869624689e 100644
--- a/tests/playwright/support/sections/FilesListPage.ts
+++ b/tests/playwright/support/sections/FilesListPage.ts
@@ -377,16 +377,16 @@ export class FilesListPage {
 	}
 
 	async selectAll(): Promise<void> {
-		await this.getSelectAllCheckbox().click({ force: true })
+		await this.getSelectAllCheckbox().check({ force: true })
 	}
 
 	/**
 	 * Clear the current selection via the master checkbox. It is a toggle, so it
-	 * clicks the same control as {@link selectAll}; call it while rows are
+	 * uses the same control as {@link selectAll}; call it while all rows are
 	 * selected to deselect them all.
 	 */
 	async deselectAll(): Promise<void> {
-		await this.getSelectAllCheckbox().click({ force: true })
+		await this.getSelectAllCheckbox().uncheck({ force: true })
 	}
 
 	/**
diff --git a/tests/playwright/support/utils/retry.ts b/tests/playwright/support/utils/retry.ts
new file mode 100644
index 0000000000000..a78274f84562a
--- /dev/null
+++ b/tests/playwright/support/utils/retry.ts
@@ -0,0 +1,28 @@
+/*
+ * SPDX-FileCopyrightText: 2026 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+
+/**
+ * Run `action`, retrying it with an exponential backoff while it throws.
+ * Meant for fixture setup (logins, account creation) that can hit transient
+ * server errors on a busy test server.
+ *
+ * @param description - What the action does, used to log the retries
+ * @param action - The action to run
+ * @param attempts - How often to try in total
+ */
+export async function retryWithBackoff<T>(description: string, action: () => Promise<T>, attempts = 3): Promise<T> {
+	for (let attempt = 1; ; attempt++) {
+		try {
+			return await action()
+		} catch (error) {
+			if (attempt >= attempts) {
+				throw error
+			}
+			const delay = 800 * 2 ** (attempt - 1)
+			console.info(`${description} failed (attempt ${attempt} of ${attempts}), retrying in ${delay} ms`, error)
+			await new Promise((resolve) => setTimeout(resolve, delay))
+		}
+	}
+}
diff --git a/tests/playwright/support/utils/systemtags.ts b/tests/playwright/support/utils/systemtags.ts
index 3c19b8c70bd3a..82233c938554a 100644
--- a/tests/playwright/support/utils/systemtags.ts
+++ b/tests/playwright/support/utils/systemtags.ts
@@ -42,15 +42,32 @@ export async function listTags(): Promise<OccSystemTag[]> {
 }
 
 /**
- * Delete all existing tags via OCC.
+ * Delete the tags with the given names via OCC, leaving all other tags untouched.
+ *
+ * @param names - The names of the tags to delete
  */
-export async function clearTags(): Promise<void> {
+export async function deleteTagsByName(names: string[]): Promise<void> {
 	const tags = await listTags()
-	for (const tag of tags) {
+	for (const tag of tags.filter(({ name }) => names.includes(name))) {
 		await deleteTag(tag.id, true)
 	}
 }
 
+/**
+ * Fixture providing a generator for unique tag names. Tags are server-global,
+ * so every tag created under one of these names is deleted after the test
+ * instead of wiping all tags, which would break tests running in parallel.
+ */
+export async function tagNameFixture({}, use: (generate: () => string) => Promise<void>): Promise<void> {
+	const names: string[] = []
+	await use(() => {
+		const name = crypto.randomUUID()
+		names.push(name)
+		return name
+	})
+	await deleteTagsByName(names)
+}
+
 /**
  * Assign tags to a file via OCC.
  *
diff --git a/tests/playwright/support/utils/viewport.ts b/tests/playwright/support/utils/viewport.ts
index ce61737242b38..fe75b0d7bfffc 100644
--- a/tests/playwright/support/utils/viewport.ts
+++ b/tests/playwright/support/utils/viewport.ts
@@ -5,8 +5,6 @@
 
 import type { Locator, Page } from '@playwright/test'
 
-import { expect } from '@playwright/test'
-
 /**
  * The fixed per-item heights the files virtual list renders with, mirroring the
  * `itemHeight` getter in `apps/files/src/components/VirtualList.vue`. Using the
@@ -54,12 +52,15 @@ export async function fitFilesListToRows(page: Page, rows: number, gridMode = fa
  * Whether the locator's box lies fully within the current viewport (top-to-bottom
  * and left-to-right). Playwright's `toBeVisible` only checks the DOM/paint state,
  * not the scroll position, so this is what tells a scrolled-off buffered row from
- * a genuinely on-screen one.
+ * a genuinely on-screen one. An element that is not rendered at all, like a row
+ * the virtual list dropped, is not in the viewport either.
  *
  * @param locator - The element to test
  */
 export async function isFullyInViewport(locator: Locator): Promise<boolean> {
-	await expect(locator).toHaveCount(1) // ensure the locator resolves to a single element
+	if (await locator.count() === 0) {
+		return false
+	}
 
 	const box = await locator.boundingBox()
 	if (!box) {