single player skin problem

Hi, a few days ago my skin ceased to exist in single player. Let me explain, in multiplayer you can see it (I see it and the other players see it) but in my singleplayer world no. I tried to change the skin, to change the layer from standard to slim, I reset it from the site and then from the launcher itself and in the end I also tried to delete the .Minecraft folder, uninstall the game and reinstall it, but nothing changes, my skin is seen only and exclusively in the servers. In singleplayer I look like Steve, could you help me solve this annoying problem please?