Custom skins not changing.

So, I go into minecraft and go to change the skin, go to custom skin, or choose new skin, and I pick the skin that I want, and then it exits out to the arm pixel size but it's of the original skin that I tried to change. I've tried doing it in a world but that didn't work sk I went out to the menu, that didnt work either. So I restart the app. And now the new skin is there. I try to change to another skin but it does the same thing and I'm stuck in an infinite loop. I can change to your skins (the ones provided) but I can't change to that, then change to a new custom skin. I have to restart the app in order to change skins.