Mine's a leaker now, too. 2020 ltz built 8/19 in Ft. Wayne. Took delivery on 1/11, 2000 miles ago.
Glass is a Fuyao E4, M1235, 43R 000072.
I caught it early, no headliner damage or rust. I'm gonna try the permatex fix, maybe buy some time until GM actually fixes the issue. Love the truck, wish it could be driven in the rain. ?