Portable Generator open ground

Being a generator that none of the rest of have likely used, there could be something "different" about it. For example, maybe the outlets are miswired, with hot and neutral swapped between the two duplex receptacles. Another possibility, maybe the generator's waveform is sufficiently flawed to be triggering some error in the EMS. Maybe there's a wiring fault in the RV that's not showing up with shore power or the internal generator. One thing that's different with this generator is that the DC output doesn't have its own winding, but rather uses a tap on the main winding. But overall, I don't see anything in the Gen4000DF wiring diagram that looks like an issue. The wiring diagram is on page 30 of the manual at this link: http://www.buffalotools.com/manuals/gen4000df-ssmanual2017_sf.pdf