Well, before I bought new TPMS sensors I'd test the batteries, or the heck with it; just put new sensors in with KNOW GOOD BATTERIES, dont just trust batteries just because they are new to you.
Your tire pressure issue may just be batteries, you can reset them using tge Ing switch (I think) and the owner's manual. ChatGTP will b e a faster, better help than Google.
Our local Ace Hardware made a chip key for my 2015 Silverado for$100.00; that's a lot less than the dealer. I suggest you give them a call and have your VIN,title, and/or registration with you.
I would look at the part numbers of the dashe's wiring harness. GM might used the same harness for all trucks or considering the cost of copper they may not. A GM district rep might know. Call chevy customer service, 1 800 222 1020 (I think) they have been very helpful to me in rhe past.
The 4 X 4 was engaged while the truck was in the body shop, most likely when they cleaned (almost detailed!!!) the truck for delivery. Thanks for the response!!@