No Access to my nextcloud - SAML

I changed the IP of my UCS 5.0. Now I have trouble with the access to my nextcloud.

Bildschirmfoto vom 2023-01-02 22-18-21

The IP in the link is wrong. It isn’t the IP of my UCS. It’s the IP of my Mail-Provider.

I read a lot of tips, but nothing fixed the bug.

Any hint? Which information do you need?