I read somewhere (on this forum or another one, but I can't remember) that the water "hose" on the inside of the gravity fill can come loose from the actual fitting. Our gravity fill is also on the passenger side and can be removed with a few screws to inspect it. Might have loosened on the California to Vegas trip.
As an aside, we use the gravity fill more often than the city water fill, since there's no pressure involved, and you don't get any air in the system which causes spurts when you first turn on the water. Unless, of course, you run some water through the taps in the city water mode (pump off) first, which I sometimes forget to do.
