Enchanted armor on zombies crash the game

I was gearing a zombie up and he had full diamond armor cuz i gave it to him with q and then i wanted to replace his helmet with an enchanted one with protection IV then it started glitching and then i punched him and it stopped i went to the anvil and then my game crashed. and also i named the zombies spawn egg Bub and also this bug only happens with a diamond helmet with protetion IV