Server 21w05 crashes

Server 21w05 crashes quite quickly. Initially the player got stuck in move - could not be stopped unless reached some obstacle (but then it would keep moving if turned). It crashed, I started it again but it just kept crashing after logging in (just 1 player). Reverting to 21w03 solves the problem.

Crash report attached.

 

UPDATE

At first glance 21w05b seems to resolve the problem. Thanks