I discoverd a weird bug which multiple the colission between 2 entity's (player and/or mob).

This bug work in the overworld/end/nether and in singleplayer/ multiplayer.

To reproduce the bug we need a chorus fruit farm using 0 tick trick, I had test 2 models : 

https://www.youtube.com/watch?v=iHh8RhJhxco (KK)

https://www.youtube.com/watch?v=WWBpd8xy3Wg (ilmango)

The bug work only in the chunk of the machine, so spawn a mob or take your friends in the chunk.

Launch one farm without placing chorus flower(with flower the bug work but it's not util), after staying several minute you can stop it and run in the entity and see that you are bump really fast when you hit him.

You are bump if you walk on the entity but the other entity will not move.
This bug seems to cause lag in server/client side but it's difficult to test it.

To stop the bug just unload the chunk on the client side be enough(deconnection or going far away)

I make a video for you because english is not my first language and it's difficult to explain.

https://www.twitch.tv/videos/591911872