Android client - cannot access

Good morning all!
I have migrated my Owncloud installation to Nextcloud succesfully.
I have also changed my accounts Android client.

If a user is not under a built-in group (admin) but in a different one, also created from scratch (users) he cannot access.
The client give me “unknown error”.
If I change the user membership from “users” to “admin”, he can access.

Now all the users are admins, but I would like to change their group.
Thank you

Seems to be the same as @ownklaut and me are experiencing.

Yes, this sounds very much like the problem I got.
Btw. the admin rights were just necessary for the initial login. After successful connection I cut the user back to his normal user rights. Don’t know if I already mentioned this somewhere.

Same here, only the initial login demanded admin group.

Haven’t tried to modify after login. At the moment it is not a problem to keep the users as admins, they don’t use web interface.