Music app keeps coming on in car...Overrides driving directions...

Hi all! Bizarre but very, very, very frustrating issue I am having. I am not even sure this is the right forum or even an Apple Discussion forum but I thought I would start here.

I have an iPhone 6 running 8.3. I have a 2014 Camry with Bluetooth. Yesterday when we were going to a party and using the Maps app (and it happened with Waze too) the Music app would start playing and we couldn't hear the driving directions! Mind you the Music app WAS NOT open. It would open and start playing a song. I would have to either open the app (if it wasn't open) and stop it that way or if the app was open I would have to swipe up to quit the app. BUT as soon as Maps app gave another direction, the Music app would start playing again.

To say I was frustrated is an understatement.....!!!! Anyone else having this issue? Any ideas on how to fix it? I checked the Setup on the Camry and there didn't seem to be any options hardly at all. I guess I could unfair the phone and re-pair it again.

Well, that's my issue. I appreciate any help I can get! Thank you, Judy