Sometimes when switching to Bluetooth audio on my 2013 Model S, the audio is playing, but it is muted. I know that it's playing because I can check the app that I'm using on my iPhone (like Apple Music or Stitcher) which shows time passing by, but no sound in the car. This can occur whether I switch to bluetooth audio from a different source (like internet radio), or even if the car is already on the bluetooth audio source. In these situations, I can always fix the issue by switching to internet radio, and then back to bluetooth audio. Has anyone else encountered this issue?