[chuckster57]

Okay, time to verify flow to the gas valve. Make sure you use TWO wrenches so you don't snap anything off.

TURN OFF propane at the cylinders. NO SMOKING OR ANY OPEN FLAMES!!!!!

Using a wrench to hold the fitting that is screwed into the gas valve, take another wrench and loosen the gas supply hose. Now have an assistant turn on the propane. You should be able to smell that nasty propane smell. If you don't then turn the propane off, and tighten the fitting TIGHT.

Odds are at this point the supply line has gotten pinched between the floor and frame, I've seen it quite a few times and the dealer should have caught it at the PDI. If you do have propane up to that point, then the issue is either the control board or the gas valve.

FWIW, my trailer is 30A and I will always use both when plugged in.