Folder Backup (Android 11, Seadroid 2.3.6) - SD Card/External Storage not showing

I try to back up one folder from SD Card - I saw in another post that this should work (and a similar issue has been fixed before: [Seadroid (Seafile 2.3.3 Android 13) upload not working with SDCard] )

For Seadroid 2.3.6, when I try to Backup a folder, under ‘Selected backup folder’ → ‘Add a backup folder’: I have now the issue am only able to see internal storage and not external storage (cannot confirm it worked under previous releases, never tried it before).
Read + Write permissions for external storage are granted.

I found the section in the code for folder selection but got no clue why external storage is not showing.

What additional information could help?