I've been pulling my hair out for a few days. On IOS 15.2 I could not get CarPlay to work anymore starting several days ago. I did all of the usual tricks, including deleting my phone from Mini settings, deleting the Mini from my iPhone network and wifi settings, and re-adding it as a new device. It would fail to connect at the bluetooth prompts after a long pause. I googled and found out that Apple just released 15.2.1 TODAY to address some issues, including "Third-party CarPlay apps may not respond to input". I installed 15.2.1 and was immediately able to connect my phone to CarPlay. https://9to5mac.com/2022/01/12/apple-releases-ios-15-2-1-with-bug-fixes-for-carplay-and-messages/
I ran into this problem with the ChargePoint app last week, and I thought it was the app being screwy. And I can report this update doesn't create audio issues like I've seen previously.