I own a 2019 Silverado and on (2) separate occasions I had half the infotainment screen disappear/go black however the radio still functioned as well as the climate control system. On the 2nd occasion I had the tuner for radio show message "tuner not available" and could not hear the radio but all other functions worked.
Both times I disconnected the negative terminal on the vehicle battery for 2-5 minutes and then reconnected it. After reconnecting all functions returned to normal. Maybe this experience I had helps some of you with your infotainment issues.
May be that's what the dealer calls a " Re-flash" and then proceed to charge you $200-$300 for their high tech service!