NextCloud Mac login not possible

Hi guys,

I moved with my TimeMachine backup (including NextCloud Client) to a new Mac.
On the new Mac there is another user.
On every restart NextCloud refused the login.
Picture 1


image

NextCloud is working and I can access it via the WebInterface.
I’m not sure and not a pro, but is ist possible that this comes from the certificate (NextCloudPi WebGUI says it works still fine) change?
https://letsencrypt.org/docs/dst-root-ca-x3-expiration-september-2021/

The NexCloud works on a docker in OMV with Debian

Thanks a lot to the pros here - I’m not sure what to do.
Beamformer