Suggest you check the HWH site and download the manual for your system. If the 500, you already have the link for it.
I would think two possible problems. One the ride height control valve on the low side of the coach. Don't know how many you have, usually 3, and don't know how they are distributed on your coach. On mine, I have two on the rear and one on the front. Some coaches are the reverse of this.
Second could be the ride height control solenoid on that side of the coach.
I don't know how to trouble shoot between the two possibilities but from experience I can tell you that HWH does not play with the ride height valve and if that is the cause of the problem then a trip to a good truck shop is in order.
I had problems with the left side and it turned out to be the solenoid valve on the left rear. HWH replaced that valve and all is well. On my coach the rear valves are above the rear axle and difficult to access.
As a work around until you can get the problem solved you can remove the fuse in the HWH control box that controls the ride height. First set your ride height manually, then remove the fuse. The coach should remain at that height. Stop occasionally and check your ride height as small leaks can allow the coach to drop down. On my coach it is the 7.5 amp fuse in the HWH control box.
Pete - Full Timing
2000 Country Coach Magna 40', CAT C10, #5892
2006 Jeep Liberty