Seeing this too, fortunately only a couple of win11 machines out there as guinea pigs.
Seems there are patches taken back to samba 4.12 from >=4.16 but UCS 4.4 seems to be on samba 4.10.18-Univention. So unless univention backport it from 4.12 or do some out of cycle component upgrade looks like UCS 5.x is the way forward… I’ve been sitting on 4.4 waiting on cool solutions repos and apps to be compatible, looks like the time is coming.