Samba Domain Name shows "X" instead of the real domain name


after using UCS for some years mostly as email and cloud server we started to migrate users to use the active directory. In this process I recognized that after joining with windows 10 computers to the domain it shows “Login to: X”/ “Anmelden an: X”. X should be the domain name I guess.

This causes also that some users need to login via windows 10 using X\username instead of domainname\username. Also a wbinfo --all-domains returns X.

would be great if someone had an idea how this could be corrected.

Warm regards!