Need an expert

Okay before I lay out my problem I will lay out what equipment I have.
On the roof of our rv I have 4-200 watt solar panels. 2 sets of series then in parallel.
Our charge controller is a 150/40 amp Mppt epever tracer with the MT50 display to program
The MT50 Display says I am pulling in 40.3v pv at 8.4amps and the mppt is converting it to 14.3v at 23.7amps, but only 341 watts.
Okay so the problem is the MT50 is telling me that I am only pulling in 400 watts at most. I unhooked one of the series sets of panels and was only operating on 2 panels in series and the MT50 said I was pulling in nearly 300 watts. I then unhooked that series and connected the other series and got the same performance. The sky is clear and the sun is directly over head. So why when I hook them both up am I not seeing 600 watts but only 400ish.
Thanks in advance
Rv Adventure Couple
Comments
If your battery is at 14.3 volts, and the set point is 14.4 volts (AGM/Sealed), then the battery bank is probably >80% full, and "naturally throttling" (battery limiting) charging current.
By the way, what is the Vmp rating for your panels? 40 Volts for 2 in series (~20 volts Vmp operational) for 200 Watt panels sounds a little off... Normally, 200 Watt panels are either 30 volt or 36 volts Vmp (there are other voltages too).
-Bill
A minor issue, but the MT50 is lying in that it claims 100% efficiency.
I am available for custom hardware/firmware development