Minecraft PE Skin Reverting to default

Great question! Ive been wondering this as well. It turns out, that after some research..... So far, there is not an update to allow you to change mcpe versions, so the best you can do is to report it on the mcpe website and request an update for this to be made. You can also wait, of course, but it will be less effective.

I have had this issue as well. What I have found seems to work, make certain the host device world setting is shared. Then enter and wait in the setting screen. At this point the other devices should see the host device world (they may have to close and reopen the world selection screen). If this does not work on first try then close and kill the app on hosting device and reopen it. By close and kill you need to double tap the home button and then swipe the app off screen to kill it.

I play all the time with my son and this issue happens a lot. Using this technique has worked almost 100% of time. If you are paranoid you can also flip the WiFi option off and back on again while waiting in the setting screen.