The DC input from the PV strings is connected with reversed polarity.
CauseThe plus and minus conductors of a PV string are swapped at the inverter's DC input, so the inverter sees reverse polarity.
Recommended fixCheck the PV input polarity.
Source:sun-120k-g01p3-eu-bm8-sun-125k-g01p3-eu-bm8-sun-130k-g01p3-eu-bm8-manual.pdf· page 61