Starting music streaming in car launches YouTube

This is a bit odd. After I start my car (Honda) and my phone connects to the Bluetooth system turning on the stereo used to auto start Google Play Music. (Note, the reliability of this auto start has dramatically diminished with every update of both Google Play Music and Android. Worked perfect back in 2014 under prior versions.)

Here is the oddity. If I have last used YouTube on either the phone or my home PC YouTube launches instead of Play Music. (On the car's BT system, not on the phone and nothing actually plays.) I have to dig my phone out of my pocket and go to the app drawer and launch Play Music. (Note, I now often have to do that anyway even if Play Music shows on the car's system as it is really not running.)

Anyone else experience this? I have cleared the system and app cache with no change. Also, there have been no updates to the car's BT system.