[pre207_mc1.21.1] When a player stands on top of a moving structure, the player's render begins to teleport.

I was with some friends on a modded server and I placed a door that opens from the floor, but when my friend stood on it, he started teleporting and we had to kill each other to fix the bug.


Here's the video
https://imgur.com/gallery/little-tiles-bug-Vkpexvl