With off grid mode disabled you have grid assist. That mean grid will help with surges. If it was a firmware problem you wouldn’t be the only on here complaining or looking for a solution trust meOK, let's say there is a problem. Why does the system work great with "off grid mode" disabled? Like I stated earlier, we have over 4500 watts of loads running on it now and it starts a 4 ton without any issues. The problem is something in the firmware that's taking away a significant amount of surge capacity when "off grid mode" is enabled (this switch also changed it from EPS to consumption).