Well, I have an update. I have now discovered that the tripping vs not tripping is related to whether or not I have a proper earth ground in my AC line to the trailer.
The extension cord I have been using to plug the trailer in here at home was missing it's ground prong. Without this ground prong, the Surge Protector allows the trailer to have AC power. I replaced the end on this cord yesterday and now the surge protector trips every time just like it did at the campground (no extension cord was being used at the CG). Since an earth ground is proper, I have now confirmed that something in the inverter/install is causing the surge protector to instantly trip.
Thoughts...this inverter defaults to an automatic mode where it monitors the load side and turns on the inverter when/if it senses a predetermined user programmable load level (0 to xxx watts). I wonder if this load sensing system is somehow causing the surge protector to trip? Also, the manual for the inverter called for a separate wire from the chassis of the inverter, to the chassis of the trailer (in addition to the DC ground).??
'04 GMC Sierra 2500HD, CCSB, D/A, MaxBrake, B&W Companion, Retrax Pro, AR Power Steps
2013 Rockwood 8289WS w/Diamond pkg
1969 Camaro RS/SS Convertible
Dad's old 1968 Empi Imp (recently recovered from under 21 years worth of boxes/dust)