While playing a two player couch co-op game on X-Box one, player 2 saved and quit and player one continued playing for a bit and then also saved and quit.  When the world was loaded again and player 2 joined, they spawned at the world spawn, and everything in their inventory was gone, along with the experience level being reverted back to 0.  We have played a lot without this happening, but since the latest update to version 1.16.200, it happened twice.  This happened on all saved versions of the same world.