Sorry that I lost track on this thread. Has the issue been solved? The other possibility I can think of would be the 8-pin ribbon cable — use a multimeter to check the connectivity on each line of the cable (the cable connectors have small openings that expose the metal pieces, you can use a multimeter probe to touch these and measure connectivity). Cable issues have happened in the past, so I won’t be surprised if one or two lines on the cable are disconnected. Also double check if you’ve plugged in the cable in the correct orientation.