I have a 2019 At4 with the 6.2. I have had the same issue with not starting but mine throws codes. If it sits for 30 mins it will start every time. The codes always show cam sensor and low voltage. I have taken it to the dealer three times. GM engineers had the dealership replace the cam sensor (nope), reprogram (nope) and the third time go through the wiring harness and replace the fuse box. GM literally has no clue what is causing it. Just got it back today. I have zero confidence it’s fixed. Should have waited to spend $55k on something that doesn’t run.
