Same issue on my Autobahn. After a phone call (my first one through the infotainment system), absolutely no sound from the radio. I rebooted the infotainment three times and no improvement (this has helped for other nuisance issues). I’m stumped.
I bought a small LED flashlight with built-in crank charger after numerous sets of batteries died in the previous flashlight while it sat unused in the glovebox.