[tygriff45]

This happened on our 2012 RS using an Iphone XR. Based on searches I determined it is a IOS 15.1 issue. If you go back to a previous version of IOS the USB functionality works

See thread below on apple:

iOS 15.1/ music not working - Apple Community

discussions.apple.com

 

[tygriff45]

The current work around is a Iphone aux to 3.5mm cord and plug into the 3.5mm input rather than USB of your car.

While we wait on a IOS update