I have been downloading and using custom skins on my Minecraft Bedrock app and find that changing the skin to any downloaded custom skin requires a reboot of the app to make it display. Otherwise, it behaves as if it has cached the previously selected custom skin, showing that one when prompting for the model type and then not updating the skin to the newly chosen one within the current game or on the home screen where the model is displayed. Only by rebooting the app will the then changed custom skin be displayed both on the home page and within the game itself. Selecting and equipping a free skin from the marketplace store is fine. Once the custom skin is displayed within the interface and the game after an app restart, the skin behaves fine, so I don't believe it to be a problem with the skin file itself.