I have a 2013 328i. Recently, when the car goes to stop (it has the start/stop engine) and then comes back on, the navigation screen goes completely black and then fades back in. It has only happened a few times so I can't figure out what's triggering it. I took it to my mechanic and they said my battery looks ok and ran some test but couldn't figure out what's going on with it. Has anyone had this problem or have any idea what it may be? Thanks!