Hi. Purchased a 2019 XL 5.3. It’s got about 50k miles. Last weekend I changed all the fluids. Drove it today and when idling the oil pressure dropped to a hair below 30. Normal? I’ve never had a vehicle drop like that when idling. Also when idling every 10 seconds or so I feel a very light movement. Normal? Everything sounds fine and drives good. Not sure what to make of this. Any information helps. Exactly 8 quarts added during the oil change. Thank you.