Tinstar wrote:
It is not a GFI problem and I am reasonably sure it has something to do with the EMS and how it interacts with the generator.
I happen to have an older motorhome without an EMS. I plug it into the generator and everything works normally and everything is powered.
You probably just need to bond neutral+ground at the generator to satisfy the EMS. Some generators will have a bonding strap that you can use to do that, but most people buy or build a bonding plug that they plug into one of the generator outlets:
https://www.campingworld.com/portable-generator-bonding-plug-118090.htmlEasy “how to” make a Bonded Plug for an RV Generator/make EMS system work with generator