I want to chip in that I can confirm the bug as well.
I tried to get into a nice fisticuff with fellow players, but as the Author already described a crash follows shortly after.
Simply running around with fists doesn't seem to crash it, but as soon as a Land audible and visibly hits,
causing damage, the Server crashes moments after. At least from the few attempts that I had with this bug.
@Omega_ I have send you a message on Discord. I'd be happy to help out there.
EDIT:
Clips have been recorded with Omega.