Units do not work in rooms they are assigned to

This happens pretty frequently with witch doctors and succubi - I think it has something to do with assigning them to rooms via dropping them into them. Drop a succubi into the torture chamber with a couple of captives on torture racks set to corrupt and they will maybe corrupt a few, but sooner or later they will refuse to interact with the room at all. I've seen a succubi with needs all at 80+ and ecstatic mood doing nothing when dropped into the room, and witch doctors will do the same.

The only way to avoid it is to not drop units into the rooms to work and to just leave them to wander in there in their own time.