I don't know what I did wrong but everytimei plug in my galaxy note 9 it doesn't work. I tried both cables and both ports but neither of them work. I need to try another phone actually.
I had issue at first with an s20 and had try another phone but same result... I believe it was showing some error message ...however if the phone reacts an give an error message your on the right track.
First verify that the time and date on both devices are correct otherwise android auto handshake will fail ... also if your phone is not updated to latest Android auto connection will fail (especially Samsung phones) mainly Android 10 n up due to wireless feature implementation and Google and Samsung conflict but its sorted out now.
Latest phone dont display Android app in app tray however you can search and it will pop up then u open it and check all setting as it relates to permission and initializing.
But the cables adapter do work... so check that none of the 4 pins are bend by pull out and visually check... other change usb cable use to phone as they are lots of poor quality and most are just for charging only..
Let us know the error message your getting to advice accordingly..