We noticed our LAN game crashing occasionally. We finally found out that it was when another player stands on a shulker box while you try to open it. It starts to open and the game freezes. you need to ALT+F4 or use task manager to kill Minecraft and restart the game. It's a hard freeze. I was able to reproduce it every time.

Here's a video showing what happens: https://youtu.be/pZdVvycfeQ0