Sorry you are having issues with AA. I have a Touring, am using a Samsung 21+ and have had no problems with AA using a 3' cable. Plugging in before or after starting the PP, it always connects. Also did not have any problems with my old Samsung S8. Perhaps trying a different phone to see if it is the phone??? Or resetting the radio to default settings and trying to reconnect the phone???Just my observations using Android Auto.
I seem to have much better results when connecting my phone before starting the PP. Connecting my phone after the car is started results in "Android device not found". Disconnecting and reconnecting doesn't help.
Also I have less issues using a longer cable. I bought 6 inch cables to prevent clutter but the short length seems to put too much stress on the connectors if the phone moves around and causes disconnects.
Anyway, hopes this helps someone FWIW, just my 2 cents.