Ethos not recognizing one of my gpus

Hey guys,
I set up a rig with 3 GIGABYTE Gaming RX 580s 8gb on a TA 970 motherboard. Two of them work fine, but the third isnt recognized by the computer.

Here's the gpus, with the one on the right not working. The right one's fan is on, but the "fan stop" LED is on. Its also a different color than the other two.


Heres the motherboard + riser cables


Here's ethos GPU detection screen. The third one is not on this screen.



Any way I can fix this? Is it a problem with the GPU?
Thanks