You need to drop the car to make it settle into ride height. The tires are closer to each other with the arms in a lower position. If you put it on the table, there's too much resistance on the tires and the car won't go any lower. Just drop it from about 7inches.
If the track is bumpy and the chassis bottoms out on the bumps, use a heigher rideheight and build the shocks with more rebound.