Nether Update, Original Xbox One.

Players will randomly receive damage or effects of blocks they are not actually standing on. This is observed personally when players are playing on my Parkour map while jumping across blocks over lava, fire, or other blocks with effects. Their character is clearly on the safe blocks, but they will catch on fire or receive the effects of the blocks below like they fell onto it. Distance is not affected.

This is observed with multiplayer over internet. The only theories I have is that the player model is de-synchronized with their actual location, as I see players falling and teleporting back to the block they "fell" off of. I believe Autosave is at fault here, or data sharing between connected players and the host.

The problem with this bug is that it makes playing highly frustrating as both the host or player. Players are constantly being damaged while doing nothing wrong. Anything that requires skill or accuracy while jumping or around dangerous blocks is completely impossible for non-host players. I highly suggest Autosave be investigated as well as a Disable option with manual save.