Newmar/Spartan Chassis Air ride control valve inverting

Without seeing a picture of your HCV setup, you may want to look at the length of the arm on the valve. Not the length of the vertical arm that attaches to the axle. If the arm, or attachment point is too close to the rotation point of the HCV then you can get this problem. The solution is to move the attachment point further away from the center of the HCV. This will dampen the response time of the HCV but will solve the problem. You may have to slightly adjust the ride height when you do this

The typical control system has a rod, attached to the air valve on the frame, and the other end attached to the suspension system. It is possible the rod is not the correct length. I believe the ends are supposed to be about 16.75"

Don't know what type of control valve you have but the Haldex Type EGP IR 90555105 Ride Height Control Valves (RHCV) have a 45 degree up or down travel from Center (level). They use the same valve for both right and left installation by flipping the spool valve in the unit. There is a small mark on the spool to indicate direction. If the lever arm is too short it can over-range the RHCV. Are both sides affected? If only one side is affected I would measure at length of the lever arm on the good side and adjust the problem side to that length to see if it helps. If both sides are a problem I would increase the length of the lever arm to see it that helps. My rear suspension has 3 inch travel up and down from level. My leaver arms are 6 inches long. I was having problems on one side and found that that side was set at 5 inches. The longer the lever arm to slower the valve responds.