I think someone posted about this same problem many years ago...
my 2010 GTC failed to initialize the infotainment system after the car was driven and restarted 30 minutes later. No radio, nav or ac/heat controls. This seemed like it could be a major issue, but I parked the car in the garage locked it and let it sit undisturbed overnight. Like magic, everything was back to normal when started the next morning. I think the head unit can be reset by removing the #17 fuse, but I didn’t have to try that. Wondered if anyone else has experienced this. Is it common?

 

It's one symptom of a failing infotainment unit. Or it could be a gremlin caused by a low left-hand battery.

The worst symptom is when it continually reboot loops even after the car is off...