BOUNTY HELP FOR 0.5 ZCASH: Getting 8x NVIDIA GTX 980 Ti GPU to be detected on Asus PRIME Z270-A Motherboard / Windows 10

Thanks to your help I managed to get 7 card recoginized in windows.
Just to note that windows must be installed in GTP partition as mentioned here:

but my 8th card which is plugged into the M.2 to PCI card was not recogized. If I insert it to a normal PCI slot using the same riser, it works
I also use the same Z270-A mobo

So, did you need to do any specific steps to get the 8th card work?

Thank you