No Screen / Black Screen with Metal Card GPU?

System: Mac Pro 5,1 -> Monterey 12.7.2 via OCLP 1.3.0

Used Nvidia GT120 for boot screen / install,. all went smoothly, machine runs fine with this GPU alone.

Problem: trying run Radeon RX480 card (which worked fine in Mojave, it is a Metal enabled card), I boot to a black screen if card solo. I can tell boot is successful by internal lights, keyboard responses etc but there is never any image (not even a boot screen.)

With RX480 + GT120 in there, I get boot screen , then it hangs at 0% on the Apple logo.

I thought the rx480 being a metal enabled card, it would just work with OpenCore, especially since it always did it in Mojave.

What are my next steps to get this card working? Or am I out of luck ??