Last night, we plugged our '17 FFE Platinum into its 220V charger as usual. No overnight thunderstorms or anything unusual like this. This morning, the car displayed "System shut down to conserve battery", despite being plugged in and the ignition being off overnight. Once we started the car, everything was fine except for the audio system. Now all it will display is "Audio off" and it does not respond to any buttons. Nav on the same screen seems to work fine. Any ideas? If nothing here, off to the dealer tomorrow.....