BungeeCord UUID's Changing

Hello,
So I was just messing around with a test BungeeCord server and I found out that it changes the UUID of the players as its in offline mode :I

This is really bad as everyone will lose all the progress they have made if I go along with my BungeeCord server on a existing server..

Is there any way of stopping the UUID change because of offline mode...

@BensDaMan @md_5 @Hexcept