RENOGY Rover 60A voltage display is to high

I have a RENOGY Rover 60A and the voltage on the front panel display is to high by about 0.7 to 0.8 volts and I beleave it is putting the charge controller into float mode before the battery's are fully charged. On a good day my system will normally charge at about 34 to 38 amps for about 3 to 4 hrs. but yesterday at about 12.30 the current started dropping and by 1PM it was down to 21 amps and would only go higher if I increased the load on the inverter. Later in the afternoon when the sun was lower the charge level dropped below my demand level and the renogy display quickly drops from 100% charge level to 80% charge level. I did try to set the float level from 13.8 to 14.0 v but that did not make any difference. Is there anyway to set the voltage on the renogy
display to the correct level?

Comments
The voltage displayed on the controller has a resolution of 100mA, the DMM is 10mA so in theroy the DMM should be more accurate however depending on its quality it may be as much as +/- 5% of what it's actually reading, 5% of 12.25 = 0.61 so the actual value being measured could be 12.86V or 11.64V, hopefully the accuracy is better than 5% but even 1% would be +/- 0.125 of actual. This is true for the controller accuracy it may be inaccurate which is more likely as it is merely an indication.
Having the meter tested against a known calibrated one will help confirm if what's being seen is to be believed, the DC voltage accuracy for the meters I have, the $100 Fluke 12 is 0.9%, the $300 Fluke 179 is 0.09%, testing between the two 179's I have is usually within 2mV (0.002V) but >5mV when tested against the 12.
Second system 1890W 3 × 300W No name brand poly, 3×330 Sunsolar Poly panels, Morningstar TS 60 PWM controller, no name 2000W inverter 400Ah LFP 24V nominal battery with Daly BMS, used for water pumping and day time air conditioning.
5Kw Yanmar clone single cylinder air cooled diesel generator for rare emergency charging and welding.
Second system 1890W 3 × 300W No name brand poly, 3×330 Sunsolar Poly panels, Morningstar TS 60 PWM controller, no name 2000W inverter 400Ah LFP 24V nominal battery with Daly BMS, used for water pumping and day time air conditioning.
5Kw Yanmar clone single cylinder air cooled diesel generator for rare emergency charging and welding.
Use your voltmeter to confirm the voltage at the battery bus (or controller Vbatt terminals). Assuming the controller is otherwise repeatable, then setting the voltage(s) to what you want at the battery--That should be good enough. (ideally, the controller and batteries would be around room temprature of ~75F/25C so you do not have the -0.003 or -0.005 volts per cell per degree C offsets (as controller temperature sensor cools, it will raise the battery charging voltage/setpoints).
The "battery state of charge" indicators on most controllers is very iffy at best. Just monitor the voltage(s) of battery bus and go with that...
Unless you want to install some other type of battery monitoring meter(s).
-Bill