Several users are experiencing issues with the system shutting down when using CarPlay with iOS 15 or an iPhone 13, but Apple has yet to make an official announcement.
CarPlay not working properly with iPhone 13 or iOS 15
There’s something about the iPhone 13 and iOS 15 that’s not quite right for CarPlay, as the feature has started to shut off when users try to listen to music. There are multiple reports from people on Apple Support of CarPlay shutting off or restarting at this point.
The issue appears to be tied to music playback (via Apple Music, Spotify, etc.) and the problem persists on both wired and wireless connections. In the case of Apple Support user bigja14, CarPlay also closes when ending a phone call.
On Twitter, @AppleSupport advised those affected to try the standard approach (reboot/install). That doesn't seem to help.
