Hey Jackwards, Your not alone !! My '19 Custom Trailboss does it every single morning pulling out of the garage. If I had to describe the sound it has the exact sound of a large bird dropping a duece or like a small pinecone hitting the roof. I have just over 3,100 miles on the truck now and it still does it every morning. I do hear it on other occasions such as if I park at work in certain areas of the parking lot then leave for the day I'll hear the roof pop. I'm actually starting to get use to all the noises these new truck's make. How about the fuel pump noise you hear each time you open the drivers door, like it's priming up getting ready for you to fire her up., Or the loud clock ticking noise the truck makes when sitting there idling like it's counting down for some unknown event. Lol. It's not the exhaust ticking noise you typically hear from the pipes heating up, it's a profound clicking noise of a fuel rail or timer of some sort.
I could go on and on. The truck definitely let's you know there's allot going on when your using it. But... This is my best Silverado I've owned so far. I don't know why but this '19 Silverado pulls my big enclosed snowmobile trailer much easier than my '14 did and I had many mods done to my '14 (Full Gibson exhaust, CAI, Edge programmer) pulling a large enclosed trailer down the road is like pulling a billboard sideways. Big parachute.
So far even with all the pops, ticks and those fuel pump prime noises each time you open the door "I still love this truck" ?