thank you for replying.
yes I know, I cleaned up MOB before. That wasn't helpful. Today I added vCenter successfully but only with IP, with FQDN was it unpossible. I don't habe any idea if this will acure any problems.
We will see.
So, after I was able to register vCenter in NSX-T Manger with IP, and it works fine, tried on the next day to change to FQDN and on funny way I didn't get any Erros... Just was everything fine...
So the right way: deregister, cleane up MOB, restert sevices, register again...
stay home and healthy