Ok, so I just swapped out my magnum inverter for 2x24v/3kW/70a multipluses set in split phase with the legacy apps. I'm hooked up to a 50a service. I check all the voltages everywhere, all good. Proper 120's and 240's where they should be, starting at the shore power in through the inverters and all the way back to the house breaker panel. Turn the breakers on, GFCI is yellow, and won't reset. I'm not hooked up to 12 volt with the inverter just yet. That's powered by a single 12v hooked up to a separate battery charger from an external 110 outlet. I did some research and checked my water heater element because sometimes coincidence happens, but no problem with that. Not sure what to do now.
Advice?