Can I use UCS shares as TimeMachine backup target from MACos machines?
Up to Samba version 4.8 there was a bug regarding TimeMachine backups.
With UCS version 4.4 we ship Samba version 4.10 where the bug should have been fixed and therefor could be used as TimeMachine target.
Up to UCS version 4.3-3 Univention does not ship Samba 4.8 (latest is Samba 4.7.8) so UCS prior 4.4 can not be used out-of-the box as TimeMachine target.
Note: There is a workaround (German) available to use a Samba share as backup target.