Forget kinked hoses, air locks etc., it is a DESIGN ERROR.
Gas can not flow uphill!
Jayco sent me the shop bulletin on how to modify the filler to raise it a few inches but it involves extensive modification of the slide out, weakening the structure and ugly fiberglass work.
I found a simple solution. Make a wooden chock that raises the wheel about 3", now the gas can flow DOWN to the tank.