I have a 2021 Silverado LT with 5.3 and 42,500 miles. A few days ago, the oil pressure at first start up in the morning would go over 70 psi and 60 at idle. After about 10 or 15 minutes it would go back to normal. I changed the oil and filter, and it is still the same. What could be wrong?

 

I would start by replacing the oil pressure sensor.