Moving a world from a local/multiplayer game to a bedrock server and vice versa does not retain player data. So say when moving a world from a local/multiplayer game to a BDS instance, the player data is not retained. After playing a while on BDS in said world, and then moving it back to local, your new player data from the server is not used, but the old one from the last time you played local/multiplayer is used instead. This goes both ways with worlds created on a server as well.

It seems the player data is stored under separate prefixes - player_<uid> and player_server_<uid>, also the ~local_player generic seems to mess things up a bit as well. As long as you're logged in with a Microsoft/Mojang accound - shouldn't player_<uid> be used instead of ~local_player? Or maybe have them be synced with eachother? Also using player_<uid> at all times, even on the server instead of player_server_<uid>? I'm guessing you have your reasons, and there are workarounds such as putting everything in a chest when moving a world to/from server/local, but still your location, hp, hunger and xp is not retained. Is this a bug or working as intended?