Questions about the skin

Hello, I've got some really bad problems. Since I updated to version 1.21.40, several issues have remained unfixed. Firstly, I can no longer upload my custom skins in multiplayer games. Although the uploading function briefly worked for a few hours after I updated the version twice, it quickly stopped working again. It's really awful. Another problem is that when I exit the game with a custom skin of thin arms and restart, it turns into thick arms. This makes some custom skins look really strange, and this happens every time I restart the game. I really hope these get fixed! Please!