I have a similar question, I have a Ford F250 with onboard generator of 2kw/20 amp outlet with gfci. When I use an adapter pigtail from RV to 20 amp male, plug it into the truck vial extension cord, the truck gfci immediately trips. My truck generator uses a floating neutral that is isolated from ground. I have not tried with home outlets yet. Is this an issue with the trailer wiring being done incorrectly or what gives? I was told to plug a neutral/ground bonding adapter into one of the trucks outlets to fix, but it too trips the truck gfci. I can run a drill fine from the truck.