I have installed 4 Hyperion 400 W panels (500w bifacial) on an EG4 Brightmount rack from Signature Solar, and I'm only getting less than 200 watts from each. I have these 4 in series and when I measure them end to end I get 129-132 volts VOC. This drops to about 120v to the MPPT in the EG4 6000 XP. That inverter wants to see at least 140V. My Solar Assistant says it sees about 700 watts for the string. These are south facing and I have tried an angle of about 32 deg and then about 28 deg with no improvement. Anyone else using these and seeing this? I'm going to take one of the panels off and play with the angle and see if that matters. Can someone recommend another brand from Signature Solar where you have measured some good output?