So I recently was kicked from a server for a reason, then I tried replicating it on single player.

Turns out that when /gamerule DoImmediateRespawn is true, when a player dies, they get sent back to the overworld, but the camera is inside the player. You can move around the soul of the player, which I've done (first image) to show off, and when traveling through the portal again with teleport, the game lets you control the player again, but without being able to place blocks. then traveled through the portal again, this time in survival. The zombies chased my original position, and dealt damage and knockback when in creative mode. Another time around, the soul was able to place blocks, and (with the player's head rotation unchanged) place and break blocks exactly where I was. Soon, I was able to update blocks using right-click. Spawning mobs was also weirdly bugged, with still mobs and mobs teleporting to high areas. With the block updating, I revealed some parts of the nether. Then that's where it crashed.