Same problem here. Even with "systemctl stop samba" it takes much time, and in the meanwhile a "systemctl list-jobs" returns this:
JOB UNIT TYPE STATE 2581 samba.service stop running 2582 samba-ad-dc.service stop waiting 2 jobs listed. -- Massimo Maiurana Ragusa (RG) -- To UNSUBSCRIBE, email to debian-bugs-dist-requ...@lists.debian.org with a subject of "unsubscribe". Trouble? Contact listmas...@lists.debian.org