This is a straight up guess since I’ve not done anything multiplayer ever, but I believe UI is facing the camera defined by player controller, so isn’t it possible you cannot always use index “0” as a player controller id?
It’s really hard to tell just from this bud that would be the first thing I’d do.
Edit: Reading it again it seems the numbers should be facing that way :D… so the only problem are the values right. Then I think it’s still the ID, but the solution is even more obvious.