I was just out in the camper looking at the furnace compartment and heat run.
I taped off the furnace to stop some of the leaks. Can't get to the bottom without opening the membrane. By the looks of it that's where the heat run is tapped into. Hopefully they secured that cause I don't feel like opening it up at this time.
Now, I think Keith (Hunter11) was talking about sealing up the heat run in the back of the unit on his. I just checked mine and it looks like there is no end in it.

It must be blowing right into the belly area.
Keith, did you seal yours up at the last out let?