Issue: Rejoining a server but with 0 experience?

Hi! Was wondering if anyone else had this problem. I hosted a server with a friend. When I went back in I continued as I left but my friend who rejoined didn't have any of his progress or items saved.

Is this common?

Maybe an important context: the first time we played I was on PC and he played from his steamdeck. The next time he rejoined on PC with the issue of the lack of progress. He tried joining from his steamdeck again but the same thing happened.