Knox won't come in house once moved in

I have the exact same issue. I think I asked Knox to move in before my sim married him, but not 100% sure. Knox will occasionally be considered not part of my active household. He is still listed and I can still tell him to do stuff, but it is not possible to click on himself, for example to practice singing or change his clothes (when you try to click on him with him as the active sim, nothing happens) and while he enters the main part of the house (through the main door) he refuses to enter his bedroom through another door, reacts as if it is blocked or locked for him, which it isn't. One time he was actually marked as "Neighbour", other times he looked normal but still had the same issues. So far, it was possible to fix the issue by traveling somewhere and return to the home lot, but still, it's annoying.

obviously it happened after eco lifestyle but I don't think it's tied to any particular patch. Also, I didn't have that problem with any other households, so I can't really tell whether it's because of him specifically, the fact that he was an NPC, or just a general thing. But the fact that others have this same issue with him makes it likely it's him specifically.

https://i.ibb.co/rsFJVDQ/Knox-Neighbor.png

Edit By Crinrict: Adjusted formatting of the post to make it more readable