2019 Denali

My 2019 Canyon has a similar problem. Typically once a day, usually after first start and bootup the infotainment system reboots while driving. When the boot starts, the FM radio plays and when it completes the usb music and FM music are both playing, the outside temperature reads "--", and a no gps icon (red circle & slash) is displayed, although the navigation system seems to work fine. After shutting the vehicle down for 20 minutes or do and restarting, the system boots without problems. A separate but related problem occurs when initial bootup fails to read the sd card with a 'ad card removed' message and a disabled navigation system. Restarting after 20 min clears this error. Dealer replaced sd card reader, but problem persists. Dealer could not replicate the system reboot problem therefore claimed could not troubleshoot or correct. I will continue to persue with dealer. Anyone know of a CTL-ALT-DEL type shortcut to reboot? I read on Consumer Reports that calling On- Star and then hanging up will cause a reboot, but have not tried it.