While playing creative with some friends, I was making parkour jumps with shulker boxes. We noticed that while opening menus, (Inventory, or containers, unknown to what else) while someone opens a shulker box, you can visually crash the game. The music still plays, and certain people remain in the world, but the others cannot move or close/open any menus, including the settings. I was host, could not easily recreate crash. Pictures were from a friends perspective.

*Edit

Apparently it happens even when you arent in menus. Big oof. Seemingly random?