Build an enclosure, of either doubled walls or a long house, that blocks off an area against a cliff, but has doors on both sides. Minions inside the enclosure won’t leave, and even minions between the walls / inside the house won’t leave.
I’ve noticed this with two doorred houses
this still seems to be an issue, which makes it hard to build second level decks
I enclosed my own camp between two doors and another time between an outer fence and inner fence. both times the heartlings would only go outside the second obstacle as soon as I removed one. I also noticed that the pathworking won’t work with a single barrier if that barrier is at some distance from the rest of the camp(it was an alternative exit through the mountain.