Greetings AnneG_1026,
To isolate the situation, are you able to, when connected to CarPlay but not driving, test to see if you can use the CarPlay interface to play music not in your Music library? We ask this, because Apple’s article on CarPlay specifically states, “Use Siri or open Music in CarPlay to play music that’s available on your iPhone—including songs, artists, albums, playlists, and Radio.” Play music with CarPlay
Here are also some steps to take if CarPlay isn’t working as expected - If you need help with CarPlay:
"Make sure that your iPhone has the latest version of iOS. If your iPhone is updated to the latest version of iOS, follow these steps — checking CarPlay after each step:
- Check your connection to your CarPlay stereo:
- If you have a wired connection, try connecting again with a different USB cable to a different USB port if you have one.
- If you have a wireless connection, make sure that Wi-Fi and Bluetooth are enabled under Settings > Wi-Fi and Settings > Bluetooth.
- If CarPlay doesn't activate automatically, look for the CarPlay logo on your car's display.
- Restart your iPhone and your car.
- Make sure that Siri is on.
- If your iPhone isn't detected by CarPlay, make sure that CarPlay isn't restricted. Go to Settings > Screen Time > Content & Privacy Restrictions, tap Allowed Apps and make sure that CarPlay is enabled.
- Go to Settings > General > CarPlay, tap your car, then tap Forget This Car. Then set up CarPlay again.
- Make sure that your CarPlay stereo is using the latest firmware from the car manufacturer. Check your car's manual for more information.
If you still have issues connecting to CarPlay, contact Apple Support."
Thanks.