Player resets with LAN

Me and my boyfriend have a world we love to play on, when my Minecraft updated he joined my world and it set him as a LAN player. It reset him as a new player which all his items were gone and he even spawned in the first world spawn point. I've opened new worlds but still showed him as a LAN player, I join other friends worlds and they also come out as LAN when they live nowhere near me. I already tried contacting windows, Xbox and Minecraft so apparently its a bug! Pls help i need this fixed asap