Are the inverters still not turning on? You didn't state explicitly if that's the problem.
Is your 8 volts of rise calculated or measured? Did you try turning it on without the taps adjusted down?
I don't see why it shouldn't work though. I'd probably be asking SMA too, if I was sure of the inverter settings.
Its weird. Here is the whole story: At first they fired up and ran fine for a few hours. Voltage was high because at that point the taps were all set at normal. I had about 255 volts. One inverter kicked off, and then the other one a little while later. The LCD displays both didnt display anything which was odd. At that point I was still trying to figure out how to log into the inverter to check settings and codes so I was distracted with all that, but I assumed it was over voltage (even though 255 should have been ok) so I decided to knock the taps down 5%. By that time it was getting quite dark so I aborted for the day. Today, the booted up fine, and the displays were working, but they went into fault immediately for grid undervoltage. I was keeping an eye on it and the lowest I saw was 228. I ran out of time and havnt tried putting the taps back up to normal. Better yet i could go 2.5% which would be in the middle of the two.
Sorry I know my procedure and info is a little scattered. I was running out of light, and trying to figure out the wifi stuff, looking for my WPA2 key, etc. Ill get a fresh organized look at it tomorrow, was just initially wondering if there was some setting I was missing. My understanding is everything should be default, and you need that grid guard key to change any of that stuff. I didnt see anything about grid type or voltage which seems odd.
PS Ok I may have figured it out. I watched a youtube video on the commissioning. I had the wrong "country standard" I assumed it was UL17412010/240 but that appears to be for a delta grid, I should have selected UL17412010/120. Ill try that tomorrow and see if that clears it up.