Some people in the world will be having the same skin as me

Some people when they join my world they have the same skin as me, or for them I have them when we're in our custom skins. The only way for me to not be their skin for them is if I wear a purchased skin, not a custom skin. This is on MCPE so what platforms can play on it, doesn't matter. Cause this has been happening to me and I have an iOS, and my friends has an android and computer.