Issues saving in splitscreen, for years now.

For the last few years splitscreen has not allowed player 2 to use their own custom skin, or retain their inventory. I have no idea why, and I have no idea why it isn't talked about more either. If we're playing on 2 different devices, it's fine, we both have our skin made and saved, it's there on our account. But if we try to play splitscreen then anyone other than player 1 has to reset every time they login. Their skin is something totally random, one of the default presets, it used to always be Steve or Alex until the new presets were added. Their items in their inventory are all gone sometimes, but the skin is consistently never saved. It's a big hassle every time we want to get back into the game we have to go through this. This has happened for years now, on a bunch of different versions of the game, on different platforms: Xbox One, Xbox Series X, etc. All I can find on this are troubleshooting steps from old threads from years ago that are abandoned, closed, no solution works at all, we've tried everything. This isn't something we can troubleshoot on our end anymore, it just needs to be fixed by Mojang..please.