Title isn't as descriptive as I would like, so here goes:
I keep my car's volume at 10. When I plug my phone in, Android Auto takes over, and music starts playing. If I turn my phone screen on, or if the screen turns on from a Snapchat message or other notification that turns the screen on, the output volume decreases. I then need to turn the car's volume up to 12 to have the volume match. This happens consistently, every time I drive.
Is this a car problem, or an Android Auto problem? And can it be solved?