While attempting to use this mod on a 1.20.1 server, the player does not start crawling and cannot fit in one block gaps. On the client side, the players view moves down into crawling position and is rubberbanded back when attempting to crawl in a one block gap.

The issue does not occur in single player with the exact same mods loaded, listed below. All mods are installed on both client and server.

list.txt