Skin not working properly

Whenever I use addons, like the ones that can replace your skin, my skin suddenly turns to steve, and all of the free skins too. And whenever I don't use them, and I ask my friends if my skin is still steve or not, they said no but instead of that, it's one of the free skins. No idea what's going on but I already have the trusted skin option turned off. What's more, whenever I try to edit my skin like for example putting on accessories, it automatically turns into another steve-like skin but with brown hair. Please, fix this issue for me!!