Skins created from character creator not loading perfectly

This was a problem without the character creator. And it still is.
My internet is slow and Lowey because I use cellular data. So it takes me hours to create a perfect skin for me. As I play with that skin there is no problem. But if I close the app and open it again a massage shows up every time that failed to load the skin. And I'm again stuck withe the Steve skin. And it doesn't affect the default skin.