When I use my iPhone for calls on CarPlay, I can’t switch back to the phone DURING a call—for example when I leave the car but want to continue my call. Settings does not work. I have to turn off my phone and call the person again.
Not sure if this will help. Did you go to Control Centre and then check the sound default. I noticed that iphone bluetooth tends to hang onto the last connection and does not change when source of iphone changes. Have lodged a bug to Apple Feedback. Tends to happen with rings, noises or most other sound things in iphone (does not seem widespread across users).
Switching to phone audio after using phone on carplay
