Alright, so I think that I've managed to fix the issue.
I reloaded a save to before I recruited him, dismissed one of my party members while he
Runs around in panic looking for Boo
and then told him to join my party the instant the option became available.
Tentatively, this seems to have fixed his follow AI. He now behaves how he should. I tried dismissing him, adding a new party member, going back to the map and walking around a bit before telling him to rejoin me and he seems to be working properly now. Hope this helps anyone with a similar issue.
I'll update the thread if he breaks again but it seems to be solved on my end.
