For over a week after the latest update, when you are playing on a specific skin, it will automatically default back to the Steve or Alex skin. We have played in the basic Minecraft as well as the Caves and Cliffs edition and it is happening no matter what skin you pick. It gets really annoying when you are playing as different skins you paid for and then it defaults back to Rambo Steve or regular Steve or Alex. It seems to be changing by the amount of distance you get away from someone you are playing with.