I and at least several others have an issue with CarPlay. Up until 15.2 when you plugged in your phone the music would start with the display on the song being played. Now it shows the top screen with "recent", playlists, artists, albums, songs, etc. You can press a button to start the music but not where it used to be.
Now that I look - this is the same screen, sort of, that you see when you start the app on IOS. Don't normally listen to music that way so not sure if that screen is what changed vs. the actual song you were playing when stopped or not.
Anyway it is not working as well and easily as it used to