I have a 2020 Silverado 1500 Z71 LT. It's certainly not a first-year problem because mine is leaking too. Same place everybody else is talking about, on the passenger, side upper right-hand corner of the rear window itself, not the slider. I live in California, the only way I noticed it was the hard water deposits dried up on the window after I washed it the second time. Not a major problem but has to be taken care of because it will get worse. I hate taking my Factory original built vehicle to those clowns at the dealer to half-ass a repair or r/r the window. It'll never be like the factory installation... But maybe that's a good thing!
