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[Bug]: Android split Settings transitions leave a stale strip of the previous page #26053
Description
Area
apps/mobile — Android Settings in a wide/two-pane layout.
Steps to reproduce
- Open Settings on an unfolded Android device or tablet so the category list and page are shown beside each other.
- Open Chat, then select Appearance in the category list.
- Switch back to Chat, then select General. Watch the left edge of the detail pane during each change.
Expected behavior
Each category replaces the detail pane in place. The outgoing page should not draw over the Settings list after the incoming page becomes visible.
Actual behavior
A wide strip of the outgoing page slides left over the category list and remains visible while the new page is already legible.
I decoded and inspected all 140 frames of the privately supplied 7.642467-second report with their original variable presentation timestamps. The repeated strip intervals are below (one-based frame numbers). The initial overlapping fades begin earlier. These are temporary rendering remnants during the native transition, rather than content permanently retained after it finishes.
| Transition | Strip visible | First frame clear |
|---|---|---|
| Chat → Appearance | Frames 6–24, 0.459300–0.759422s | Frame 25, 0.776511s |
| Appearance → Chat | Frames 36–54, 1.525867–1.826089s | Frame 55, 1.842700s |
| Chat → General | Frames 64–83, 2.961422–3.277978s | Frame 84, 3.294622s |
| General → Providers | Frames 93–112, 4.226489–4.544356s | Frame 113, 4.560722s |
Environment and impact
- Reproduced on
mainatdc84b0962efa4f4e05ef392c08986a9cd7c994d1. - Android 17 Samsung-style fold emulator, unfolded; native dev client fingerprint
477174a5a74aa551a616a4af0f7a860b99d1ff72. - Cosmetic transition defect. Local preferences pages reproduce it; no provider or connection failure is needed.
- Android’s native default transition translates the outgoing screen left for 450ms while the incoming page becomes opaque much earlier. Settings is missing from the existing no-animation policy for split workspace destinations.
Search and scope
Searched existing issues and open PRs for Settings transitions, animation, glitches and stale strips. No matching report/fix found. The open Settings environment-derivation PR #25509 changes state derivation, not navigation transitions. This report is independent of the collapsed-rail corner fix.
The original recording contains private account and machine details and is intentionally not published. The public evidence below uses isolated synthetic demo data.
Synthetic native reproduction
Before transition recording · Fixed transition recording. Both run Chat → Appearance → Chat → General on the same unfolded emulator in T3 Code dark.
Activity