The issue appears to be the cable itself (a blue cable coming from the HMI). I went behind my glovebox and touched the cable a little, causing my screen to glitch around and black out if I moved the cable a certain way. I unplugged it, cleaned off the mini USB connector, and replugged it. It will still do it if I move it a certain way, but it's now not as sensitive. Dealer even said it's likely a bad cable based on the error message the truck was giving on it. Does anyone know what GM part number this is? It sounds like replacing this cable will fix it.