Mine goes every couple years on my 07 tahoe. I use ac Delco, but it’s pretty easy to replace. Just climb up in there and reach all the way back, and you can get it without taking anything off. I would recommend putting some tape on the socket so you don’t drop it because it’s been 4 yrs, and I’ve still not found that last socket.

Did you replace the tiny screen down in the sending unit hole?

Could be a crusty connector /wire: GMs are known for instrument pannel issues.

Can alway hook up a manual gauge and monitor actual oil pressure.