When my friends go out of my render distance or I go out of there's, when they come back in my render distance or sight there skins appear as a skin of Steve or Alex with the character customisation skins

When my friends go out of my render distance and I cant see them anymore, when they come back in my render distance or sight then there skin turns into an Steve or Alex, this only happens with the character customisation skins, not ones from the store or skin packs, this happens to all my friends and it never used to, please help we love the character customisation skins and we cant use them for now, thank you very much