Worlds Completely Reset

Multiple times when I had played in my friend's realm server, overnight the realm would just disappear and be replaced with a whole new world, where everything that was built is just gone. New seed, new spawn, no items, he doesn't know why it just keeps happening. 

His gamer tag is SoulsShardsGames

My gamer tag is JHUNT72

We play on Xbox One Bedrock Edition Minecraft