On my 2005 Excursion when first using it, I have forgotten to both drain the air bags before using the levelers and forgotten to refill them before driving off. Once I remembered, there didn't seem to be any problems.
I haven't tried to drive off while the levelers were still down (yet). If you haven't tried it yet, I'd lower the levelers again and bring them back up. I'm not sure how this would help, but considering the air bags wouldn't refill after usng the levelers, it's my only suggestion.
I assume you have air pressure or else the MH wouldn't move.
While you use the air bags and levelers in conjunction with each other, I don't know that they're connected to each other allowiing the non-raising of the levelers to affect the airbags.
As far as I know there aren't any fuses related to the air bags.
With the MH engine turned off so that there's no noise, can you hear the air bags trying to fill when the the lever is turned? I've wondered that if you drive without inflating the air bags, can you pinch them causing ahole in them? If you hear air trying to fill them, this might have happened.
Let us know when you figure it out.
Bill
Nodwell RN110 out moose hunting. 4-53 Detroit, Clark 5 spd, 40" wide tracks, 10:00x20 tires, 16,000# capacity, 22,000# weight. You know the mud is getting deep when it's coming in the doors.