Could someone be so kind to provide some insight into how the FLCS stick (shift registers) should be wired onto an Arduino Micro with MMJoy?

So based on the image posted by KBird, I've got the following:

Ground (green) on GRND pin
VCC (brown) on the 5V pin
SPI-SCK (orange) on the SCK pin (pin 1 top right)
SPI-CS (red) on A0/F7 and configured in MMJoy as such
SPI-MISO (yellow) on D7/E6 and figured in MMJoy as such

And here's my MMJoy:



But my problem is that no button presses are registered at all in the VKB Keytester? So I think it must have wired something the wrong way around but I can't quite find what the problem is.