1.14 Interfere with the other players’ gameplay, mechanically restricting their access to locations or NPCs. (for example, blocking access to the GC with summons, pets, transformations, etc.).
There was this case even in a past (check) and a result was denying acces to RBs inside castles. It seems this "fix" wasnt implemented on 2.0 client so people started to abuse this game mechanic again. Its not some bug exploit but its against the server rules (nobody can access this NPC since doors are