I went through a very similar experience 3 weeks ago with the Power Gear Levellers on our 2014 Southwind.
I was told by one dealership it was the Leveller Control Box, a $400.00 USD piece of electronics located by the fuse box and Magnum Inverter.
Fortunately, it was not this item.
After an exhaustive search through every possible fuse, and fuse box, and having 2 dealerships try to find the problem, I finally located a 25 amp inline fuse (not in any fuse box) but up high in the dash behind the speedometer!
Sure enough, that fuse powered the levelling system, and, the chassis blower that also was not working.
I changed the fuse and now everything works great.
The interesting thing I realized after the contortions I went through reaching the fuse is that had I removed the top access panel on the dash, the fuse was immediately below it.
Nowhere in any manual or online did it show an inline fuse, but fortunately I was able to locate it and have made notes for the next time.
All the best with your issue.
2014 Fleetwood Southwind 32VS 🇨🇦