In case you still didn't figure it out, see this video... it's an annoying bug, actually. not sure it happens to everybody .... After pressing 'back', you must scroll up the slider TWO TIMES before you see the main menu again. Once you can recover the main menu you can save the waypoints.
Raintyre, thanks a lot, I was realy feeling I was loosing my mind, everybody told mee to "save waypoints", but the menu was gone for god. I´m happy you took the time to make a screenrecording to show me.
