This is probably late if you're flying out today but since the RV and the generators both have "floating grounds" you need to get a ground connection between the RV and the generators.
Go to a hardware store and buy a replacement 3 prong plug. Get a small wire, it doesn't need to be big, you are only having it see a connection, not carrying current. A single strand off of a stranded wire is sufficient. Connect the NEUTRAL prong to the GROUND prong.
DO NOT HOOK ANY WIRE TO THE HOT PRONG! Now, plug that into an outlet ON THE GENERATOR itself.
A picture is at the bottom of this
page of a previous thread.
2013 F450
Towing 2013 Lifestyle 37RESL