I currently have a galaxy note 10+ I use a cable to my aux port which plugs into my car and have a USB-C adapter for the phone. The sound comes out of my vehicles audio system great but I cannot use the phone to talk, the microphone does not seem to be active?? Any ideas of further steps to take, I am at a loss.
Have you tried this set up with another car? I would recommend testing your device with a Bluetooth set up to see if you still experience these symptoms.