Most of the oil should return to the pan after around 5-10 minutes or so.
Try checking the oil level at operating temp after the car has been sitting on the level ground with the engine off for at least five minutes.
If you check the level immediately after shut-off, it will indicate lower than its actual level.
1999 Dodge Ram 2500 Cummins Diesel
2002 Harley-Davidson Fatboy
Merlin Extralight w/ Campy Record