Univention-domain-join-cli incomplete

I have joined a server Ubuntu 20.04 to my Univention domain today.
It worked, more or less.

i can see the computer object in Univention and a “sudo login -p Administrator@xyz.com” or “sudo id Administrator@xyz.com” works.
BUT “realm list” returns nothing.
Also, trying to allow ssh logins, “realm permit -g ‘Domain Admins@xyz.com’” returns “realm: Couldn’t find a configured realm”

Manually leaving and joining again also does not work, as “realm leave XYZ.COM” also returns realm: Couldn’t find a configured realm".

Please help.