Weird problem! I don't have too many ideas what it could be, but there are a couple things you can try/check. Take a close look at the lamp row connectors on the driver/mpu board, they're at the bottom right. You'll notice 2 connectors, one with all 8 row wires, and another same-size connector with just 1 red/grey (row 8!) wire on it. I'm thinking, maybe you have the 1-wire connector installed one pin to the right, perhaps? That single wire on that connector should be plugging into pin 9. Make sure yours is plugged in properly! Here's a pic on my Getaway of the connectors I'm referring to. IMG_20190206_021603.jpg
If the connectors are definitely installed correctly, i would pull the connector with all 8 row wires and check for resistance of any sort between pin 9/row 8(red/grey) and pin 8/row 7 (red/violet) on the board and also check between the 2 pins on the female connector. Other than that, sounds like it could be a wire or diode touching something on row 7 or 8. These can be tricky to figure out...
Good luck!