Great! Thanks,
@CaseySJ. The OpenCore schema errors are resolved. It was due to an incorrect file update transfer between older OpenCore versions I had.
This is the sample photo of my AMD 6900 GPU in PCI slot 0,1 and lane x16. When I delete and re add the device property for slot (0,1) GPU, it fills the model name with "???". I just swapped the old graphics card and sold it. I replaced it with AMD 6900 and the device properties doesn't recognize the model for some strange reason. I really don't want to wipe my entire M.2 SSD just to do a fresh install to see if that fixes the issue. This is just my opinion, but, when I changed and kept all the config file, the same after changing the GPU graphic card worked like a charm. But it just doesn't seem to be picked up by system device properties correctly. It is supported by Apple. It's a reference model no 3rd party vendor...