Grid Lock Desync

[JasonHorkles]

On Paper 1.21.1-40, LD 10.0.44-SNAPSHOT with PE 2.5.0+ebe73587f-SNAPSHOT, the grid locking doesn't seem to work properly at all. Over time, the player becomes totally desynced from the falling block and it doesn't update until they jump. It's easiest to reproduce the issue while crouching and moving around. I can get a video if necessary