Electrical problem

It could also be that your GFCI is faulty. They do wear out over time. Try replacing the GFCI but be sure to get one with the same amps as the one you are replacing.

/\ great answer from KD4UPL.

donn0128 wrote:
The surge from the converter is probably tripping the GFCI. Happens to me at home some times. Plug in, then reset the GFCI and see what happens.

A surge will not trip a GFCI, they are only looking at current imbalance in the hot and neutral wires.

Your RV obviously has a ground fault somewhere. When plugged in at an RV park to the 30A or 50A outlet it doesn't show since those aren't GFCI outlets. Same thing as when you plugged into a non-GFCI outlet at home. Obviously it isn't the GFCI at your house because it works fine with something else plugged in.
You do need to check the RV and find and correct the ground fault. It has the potential to make for an unsafe situation where someone could get shocked. As mentioned, the refrigerator circuits and water heater are the first suspects. Turn those breakers off and try plugging in again.

Could be a failing refer 120 volt element. Try unplugging the refer in the outside access.

Had that same problem several years ago on a previous RV...the electric heating element in the water heater was burned out, and when the water heater tank was full it made the GFI trip but not a non-GFI circuit...turn off the electric switch at the water heater or disconnect it to see if the problem goes away...if it does, go to Lowes or Home Depot for a new one.

The most likely causes of a ground fault are the refer, HW and outside plugs. Turn off all RV CBs, plug in then turn CBs on one at a time to see if you isolate the problem.

The surge from the converter is probably tripping the GFCI. Happens to me at home some times. Plug in, then reset the GFCI and see what happens.