Hello since the iPhone upgrade some months ago, when my phone connects to sync, I can't hear any volume on my sat nav on the phone. I used to have an option to have the volume come from the phone or the car speakers but now I have neither. And it doesn't matter which map app I use. The only way I get sound is if I switch Bluetooth off but then I obviously can't take calls. Does anyone have an answer how to resolve this please? Thank you.