EG4 18Kpv low output off grid

I just installed a replacement EG4 18Kpv off grid.  I am trying to troubleshoot the issues.  Issue number one is the vBusP(v) output is low and highly variable.  For instance, the "steady state" hoovers around 183.4 which I was told it should be around 195-200.  The high for vBusP(v) can jump up to 211.4 like today.  The former EG4 18Kpv had this same issue, but it would also drop very fast momentarily down to as low as 135.6, which was the cause of burning out 13 low voltage transformers in our house.  Issue number two is that the voltage in the house is low as well.  For instance, on the prior inverter the voltage in the house was pretty steady at 119.3v until you plugged in the Keurig and it would drop down to 117.5v (and the total loads for the house was a measly 2200w).  On this new inverter, the "steady state" voltage is 118.4v and when you plug in the Keurig it pulls it down to 116.5v.  I'm less concerned about the voltage as I am about the low voltage sag that is burning out these low voltage transformers that in our furnace, our furnace zone controller, our garage door openers, our exercise bikes, etc.  This has gotten very expensive at this point.  Has anyone else with an EG4 18Kpv had this same issue and if so, what did you do to correct it?