Hi Paspallum,
I am having the exact same problem as you with Samsung evo plus 2TB NVMe M.2 SSD V-NAND on Orico PSM2 X 16 or PSM2 X 4 , I have followed everthing method possible as advised on the net but unable to make it work, even as a data disk. Have you managed to get it to work on the PCIe...