Audio source does not change automatically to iPod or Bluetooth Audio mode

Symptoms

["For best results, use the native music app. Performance of music control function while using Podcasts, Audiobook or other 3rd party music apps may vary.", "For best results, play media already stored on your device. Streaming music or playback from cloud storage may degrade performance.", "Switch the source manually by pushing the AUX or MEDIA button on the vehicle audio system or the SOURCE select switch on the steering wheel."]