Chunks Won't load, 1 Fps

Dear mojang studios when I am starting up the latest 20w22a version of minecraft its fine, but when I go inside off A world of server, it is not so fine. Even if the world is in the right format.. I am just getting 1 and 0 frames per second (Fps) and the chucks won't load.
oh and 20w21a is working just fine.