All non-binary documents vanished after upgrade to 5.4, only top level folders left

[kqcav]

But in a way you're up to something:
This group ›staff‹ is only defined in Cloudron, not in NC.

Maybe user_ldap also fetches group assignments from Cloudron no matter if defined in NC, wheras ›OpenID connect user backend‹ only fetches those available in the app / in NC.

I'll try that.

[kqcav]

No, that did not resolve the problem,
even if ›staff‹ is also a group in NC and the users are assigned to that group,
our files & folders (below top level) do not show up in the NC interface.

[kqcav]

Also:
independent of group assignments, NC doesn't even show a user's own files (but it probably should, shouldn't it?)

[pbischoff]

@kqcav I hope you made it working already, but I had the exact same issue after updating from NextCloud 4.23.4 to version 5 (which changes auth from ldap to oicd) and could solve it.
In my case almost every file and directory we use in our Nextcloud, where files from one Nextcloud user, that was sharing it with a group of users. We had to login this user with the new oicd "Login with Cloudron" and all files and directories were back again.