1.20.1 sync issue between friends

[StarSteveXD]

Me and some friends have a custom minecraft server running and the display is not synced up between us. It loads the same url, for example youtube but, it show us different videos, or for one player the video is playing, for the other its pause and the third guy doenst even have the video. Other cases, we wanna watch anime on a pirate website and everyones minecraft client except the host's crashes.

[IttoSanzzo]

As I see it, multiplayer sync is not supported, every player has it's own local instance