I just went out and checked whether my 2019 SUV's usb port will work with my Note 20 Ultra 512 Gb ...... it doesn't. Bluetooth is fine. I connected a Western Digital 256 GB HD and it didn't connect either. I learnt this since 2010 with my first SUV. Sony stereo.... same thing. Bluetooth is fine and didn't recognize the phone's HD. It recognized a 8GB Flash drive however.
Thanks for checking. I looked at my owners manual, it doesn't give a size limit except to say it will not work with a dedicated external hard drive. if what is happening with yours is the same issue as mine it **bleep** as I won't be able to use Android auto when I want to.
This advice was one of the steps needed to get it working. I took your advise and gave this a try, on its own it didn't work but I remembered reading on another forum someone said to go to developer options and turn on USB debugging so with the superfast charging still turned off I turn on USB debugging and it works! The car stereo plays tracks off of my phone and everything is controllable through the car stereo itself, and or the steering wheel controls. Thanks Tallman for setting me down the right path. 👍🏽 The screen displays track name, artist name and a picture, the only odd bit is it shows "indexing" on every track. I'll keep using over the next few days and see if anything changes, I'm also trying to see if GM has an update for the stereo through the dealer. Still can't get it to work at home but I'm checking with the receiver manufacturer to see if I have it configured incorrectly. Again I want to say thanks for the help!