I have a customer who has an intermittent lowering issue. If you lift and immediately lower, there is no problem. If you lift and wait a few seconds, it sometimes will not lower. You have to lift it an inch or two and it will work. If you go into the on board display, the readings are okay on lift and lower valve. If you manually try to lower, it won't. We repacked the free lift cylinder and replaced the flow and check valve of the free lift cylinder. It will not lower still. By the way, it will happen on the secondary cylinders too. Any thoughts?