Total Commander

Could you try to install an app from the play store which puts something in the obb folder? The smallest I have is this app:
https://play.google.com/store/apps/details?id=com.refugio3d.flightvrdemo
It only uses 6.9MB in the obb folder.

2ghisler(Author)
I installed that app. Then when open /obb/ in Total Commander for Android, I can see 2 subdirs:
com.android.vending/
com.refugio3d.flightvrdemo/

Both created in the same time as app installation. In the latter subdir TC also shows a file
main.7.com.refugio3d.flightvrdemo.obb
which size is about 6.9 Mb.

TC still doesn't show "-> Installed apps" pseudofile in /obb/ though.

Google's Files app opened with a button mentioned in my above post also shows same dirs and the file under /obb/ (but /obb/ itself it is still invisible in SAF dialog opened by TC's Home folder "+" item).

So it looks like the /0/Android/data/ dir is restricted on this device, because in TC I need to enter /-> Installed apps/ there to see its content in TC, but it seems there no such kind of restriction for /0/Android/obb/ dir, so probably this is why TC doesn't show /-> Installed apps/ in it.

I don't know how exactly Android 11 restricts access /0/Android/data/, but if it helps, there are access rights of /data/ and /obb/ as shown by TC:
/data/:
Permissions: 771 (drwxrwx--x)
UID: 0 root
GID: 1015 sdcard_rw

/obb/:
Permission: 770 (drwxrwx---)
UID: 0 root
GID: 9997 everybody

And, just for comparison, the access rights of /0/Android/media/, whish is shown even in SAF dialog, are the as same rights of /obb/.

tramp20 wrote: ↑2021-03-17, 12:01 UTC Give Total Commander Root Permission.
Go to “mnt/pass_through/0/emulated/0/Android/data” directory
There you can access the data folder in android 11.

Confirmed that this is working on my Samsung Galaxy Tab S7 (SM-T870) too. I created a bookmark in TC for quicker access.
Maybe this works for you too.

2ghisler(Author)
So is it possible to tell with information from my above post whether it's OK that TC doesn't show "-> Installed apps" item in /obb/ dir of primary partition on that device?

Same problem with new Andriod 11. I did not set root to the device.
Samsung S20FE, Android 11, Tcmd 3.24.

Internal: Android/data has the entry "-> installed apps" which opens the folders
SDcard: Android/data is missing this entry "-> installed apps"

Interessting, X-plore File Manager app has no problems accessing android/data folders
on SDcard as well as on internal memory path, after granting access.

I see there is another thread, also no solution so far appart from rooting:
viewtopic.php?t=72778

In my tests with my Galaxy S10e, reading from "Android/data" on SD Card does work after some security updates with X-Plore, but writing to any of the sub-folders in there fails. Therefore I have not enabled access to "Android/data" on SD Card in Total Commander.

Can you write to "Android/data" on SD Card with X-Plore on your device?

Ok, confirmed, X-Plore has no full access. Info also here:
https://www.lonelycatgames.com/docs/xplore/known-problems/no-android-data
https://www.lonelycatgames.com/docs/xplore/known-problems/write-external-storage

I tested:
- can see all folders and files, ok
- can rename and delete exiting files, ok (surprise)
tested on sdcard (I had no other folders with files fresh device):
..data/com.google.android.youtube/files/offline/B_MH3Jeoxyz/streams/6fcdxyz.uid
..data/net.osmand/files/xyz.obf
- can "not" copy from / to folders between internal memory / sdcard

Then I used USB cable on PC / MTP protocol (not the best because refreshing can fake you)
- surprise, I can see all folders and files (apart from the hidden .files, obvious)
- I can rename, delete, move/copy to/from PC (proven by reconnecting USB, and refreshing X-Plore)

So, we are in hands of Google, or some wizards
At least thre is a workaround without removing the SDcard (for huge Osmand files for example),
but if .files (hidden) have to be edited/deleted etc, the SDcard has to be used external.

Anyway, thanks for you tests.
If you find a wizard, let me know

- can "not" copy from / to folders between internal memory / sdcard

That's what I have observed here too. I can create files, but I cannot write to them, they remain 0 bytes long.