I agree with your logic
Having one or more different files and databases in the OSB?Zip file should make no difference at all.
For the heck of it I did another backup and shared to Google Drive instead of NextCloud and it worked fine.
I can't think of any reason why Nextcloud would happily accept files shared from V5 and it used to tak my Backups from V6.
So, I messed about a bit this morning trying different things.
I created a different location for Backups at NextCloud/OpenSong Backups instead of
NextCloud /OpenSong/Backups . I was thinking maybe my Backup folder should not be in the main OpenSong folder and realized that there is no need for the Backup Folder to be synchronized locally on all my devices since it might be a waste of storage space.Sharing the Backup files failed with same message no matter where in NextCloud I tried to share it to.
Wondering - when the Backup file is ready to share - has it already been created locally? Is it then uploaded and then deleted? or?
I hope that your idea about checking "that it correctly gives permission to the FilePicker to
share the file - Android has made a lot of permission changes for files
and folders and what apps can and can't share." turns out to be the issue.
It seems like it must be something fussy like that.
Thanks