I've been having a problem for a while now with my NEX 4100 and I have  been unable to solve it.

 

During Carplay playback of music that is on my iPhone 6 local storage I will periodically have the audio volume lower itself and then come back up, exactly like what happens when a new notification comes in on the phone, except there is no notification.

 

I don't have the problem on any other hardware I listen on other than the 4100.

 

Has anyone encountered this, is there any solution to the problem?