Same problem for me. And after less than a day the problem returned. Hopefully Ford and Google solve this soon. I didn't spend $60k for a damn computer that doesn't work!
The lockscreen fix did not work with my S21 Ultra, so I tried this solution and it worked!
Delete all vehicles in the Android Auto app, turn off location, then go into the app settings and press Version 7-10 times. Next, press the three dots in developer settings, then check Add Wireless...