I have a S9+. It is on the latest version of Android 10. I also have a Sony radio with Android Auto that is on the latest 1.27 firmware.
When I connect to the radio USB cable to the phone, Android auto tries to connect. But says there is a permission issue in turning on notifications and I need to go to phone. I have reviewed all Android Auto application setting and all permissions and notifications are turned on.
Keep in mind, I just tried my wife's A5 phone and Android Auto worked fine. This tells me the USB Cable, and the Android Auto are just fine and working.
I read somewhere here that someone had the same issue and it was fixed by some type of USB adapter.
Please assist. I do not want to upgrade my phone, as it meets all my needs.