I have 2 identical Deye 8 kW inverters operating in parallel with identical settings. Each has an identical set of solar panels 4 strings, 9 in series 300W nominal. 4 strings connected into the 2 MPPT controllers of each inverter. The Voc are virtually identical for each string at about 320 V DC. With good sun the panels will work at 270 V and 15 A per MPPT. For one of the inverters however the voltage slowly drops to 135-140 V and the power reduces while the other continues at 270 V. If I turn off and turn on again the DC on the one where the voltage has dropped it goes back to 270 V but then again slowly drops back to 135-140 V. Does anyone know if there are adjustments that need to be made to the MPPT controller settings or have any other idea why i have this problem.