If you have verified that all of the wires are going through the correct holes in the display board, then it's probably going to continue to be an intermittent light. I would just ignore it. As long as the volts are 30 to 32 when not generating and 24 to 28 when generating, the power is fine. Check the diagnostics periodically to verify correct operation. You could replace the display board if you want, but I don't think that it's worth the money.
Perhaps try removing the display board and spraying some contact cleaner in the holes.