Venus v3.50 Showing Red on Medium Load

Why is there a red line on the Inverter box and on L1 at 1600W, when I am running two Quattro 24/5k in Split Phase?

System:
x3 Pylontech UP2500
x2 Quattro 24/5k 1x120V, Split Phase

This happens on and off Grid. If it is an Overload Warning/Alarm feature why is it happening at 1600W on a 5000W Inverter? System is operating at 70F right now, so derating is not significant.

I think this is an easy questions, any thoughts are appreciated.