I had the same situation as you…you have to take the RS into Ford dealer service. They’ll replace some components, including the armrest usb jack. Cost me $150, but CarPlay works fine now. That fee also included a firmware update for Android/CarPlay. Auburn Ford did mine.
Appreciate this is an old thread but, having just picked up a 17 plate RS I’m having this issue where my system just crashes and locks up with CarPlay.
went back to the dealership yesterday where they carried out a diagnostic check and tried to tell me the phone was at fault. Of course I explained I’d tried 2 different model iPhones and eve tried new cables. The dealership says it’s at a loss and has no idea.