I keep the screen of my entertainment system on the Home screen (except when navigating). But there are two (so far) events that (a) take the screen away from the Home screen and (b) does not return the screen to the Home screen, and this is when my iPhone is attached via USB and using CapPlay:
- When a text message comes in. I see a banner across the top of the screen, the screen switches to the CarPlay screen until the message banner disappears, and then the screen leaves itself in the Music screen.
- When a reminder notification comes in (such as a birthday reminder). I see a banner across the top of the screen, the screen switches to the CarPlay screen. In this case, this stays displayed (at least, for as long as I was able to be patient).