Tracy Pierson

I changed out the batteries in my 2018 Silverado Duramax yesterday and am having the same issues. All comfort systems are out (including the heat) as well as the center screen and the digital part of my dash display. I'm getting a lot of warnings as well and am unable to clear them. Hoping someone has some ideas. I disconnected the negative leads on both batteries, turned on the headlight switch and left it for over an hour to drain the computer. Just reconnected it and nothing changed. Would appreciate any help.