This is my experience, how is this still a bug
It happened after I created 4 PCs through direct connect, put one away and now she won't follow anyone. Also she's my bard so not who I want to be looting and entering first! ugh
I've tried so many things, killing her like threads suggest, removing everyone, removing her, building the party back up, going on adventure with just her and NPCs, leaving her in the wardrobe while i do the same
It cannot be hard to reset all this stuff when you group or sleep - or better yet add an option to "follow" (why isn't this in there already if they can follow, I don't see much of a game play reason to not be able to follow anything)