I’m also seeing this with wireless CarPlay to my car, the iPhone will not switch audio to the car automatically as it always did and should for iOS 17.
You can go into the sound settings on your phone and switch to CarPlay
However then I get another issue. What happens is that the sound is really bad quality, as if it’s connecting with the most basic Bluetooth audio standard (what we used to use for phone calls) and not the high quality audio streaming.
Occasionally after about 5 minutes the phone works it out and the audio quality improves. All the bass suddenly comes in etc.
My sound is “skipping” occasionally but I think the quality is fine. I have also had the CarPlay crash and reboot a couple times during playback. Wireless Pioneer system.