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-7k-g02p1-eu-am2-sun-7-5k-g02p1-eu-am2-sun-8k-g02p1-eu-am2-manual.pdf· page 50sun-9k-g02p1-eu-am2-sun-10k-g02p1-eu-am2-sun-10-5k-g02p1-eu-am2-manual.pdf· page 50