[Question] - fbind unmount-mount behavior

[Mark-Joy]

Hello,
Thank you for your awesome software!
I have some question about Unmout-Mount behavior.
Here are my observations, I am not sure if the behaviors are correct or not.

I am on Android 12, LineageOS 19.1
Say if I have:

• At first, fbind did NOT start, the folder was NOT mounted.
• Config.txt: from_to "myDir" "myDir"
• imyDir is short-name for "myDir" in Internal SD card. imyDir contains file intSD.txt
• emyDir is short-name for "myDir" in external SD card. emyDir contains file extSD.txt

1> If I run fbind -m, both imyDir and emyDir now contains extSD.txt.
Question1: What happened to intSD.txt? Was it removed?

2> If then I run fbind -u + fbind -m or just fbind -um, I got error.

:/data/data/com.termux/files/home # fbind -u

Unmounting...

<...emulated/0/myDir>                             
- Done

:/data/data/com.termux/files/home # fbind -m

Bind-mounting...

</mnt/media_rw/430B-16F1/myDir> </mnt/user/0/emulated/0/myDir>
Failed to resolve mount point `/mnt/user/0/emulated/0/myDir': Transport endpoint is not connected
(i) Trying "mount -o bind"...
losetup: invalid option -- s
BusyBox v1.34.1-Magisk (2022-03-22 04:11:29 PDT) multi-call binary.

Usage: losetup [-rP] [-o OFS] {-f|LOOPDEV} FILE: associate loop devices
        losetup -c LOOPDEV: reread file size
        losetup -d LOOPDEV: disassociate
        losetup -a: show status
        losetup -f: show next free loop device

        -o OFS  Start OFS bytes into FILE
        -P      Scan for partitions
        -r      Read-only
        -f      Show/use next free loop device
mount: losetup failed 1

- Done

:/data/data/com.termux/files/home #

Question2: Is this the expected behavior?

3> I then went to "Internal SD card" and saw a file "myDir". Yes, it's a file, not a folder.

I deleted it. And after like 3 seconds , magic happened, the imyDir folder re-appeared out of nowhere with intSD.txt inside.
Apparently, the intSD.txt from question1 did not get removed, it was just hidden somewhere.
Question3: Is it the correct behavior?

Now, after deleted the file myDir, I am able to do fbind -m, and again intSD.txt was hidden somewhere (maybe?)