I just upgraded to NC 12 and installed the calendar and contacts apps. As soon as I did so, my carddav app on my android immediately started giving me authentication errors. It won’t accept my username/password. (Yes, I’m using the right username and password) My caldav app accepts my same un & pw still for that but it won’t for carddav. I was wondering if there is something about the contacts app that requires something different for un & pw or if anyone else has had the same issue.
There are a few bugs in NC 12.0.0, today a large bugfix release was published, try to use it:
https://nextcloud.com/changelog/#latest12