Acolyte/Lich with 2 skeletons (warrior+archer) and 1 bone golem. On exiting Great College into Imperial Welryn, the minions didn’t follow, although their portraits remained. The minions reappeared on taking a portal to town or waypoint to another zone. Persisted on multiple entry/exit attempts and after starting a new game.
Edit: oops, searched for Great College and didn’t find any posts, but I see now this has already been reported.