I was playing in a multiplayer local hosted world with 2 friends. For one of my friends the world kept freezing, meaning we were frozen on his screen and he somehow became desynced with the server. He was running around the world while the game thought he was frozen in place somewhere else (= we punched him and he was taking no knockback on our side); on his side we 2 were frozen in place and didn't move despite us running around with him. He was able to go through walls. It happened multiple times druing the same playsession, rejoining fixed it but it kept happening again. 

Never seen this happen before the 1.19.63 update. I attached some clips because the bug is quite hard to explain.