X210 - PCI root bridge for M.2 slot?

[flyingfishfinger]

Hi,
I'm trying to figure out why none of my PCIe cards (none of which are actually NVME drives) will show up in the M.2 slot. I've enabled all 9 root ports in the BIOS and set them to x1, since the card I'm testing with is an x1 card (Sunix UDP2018).

I can get it to show up just fine in the WiFi slot (root port 4, I believe) without changing any settings, but whatever I do, it will not appear if I put it in the M.2 slot. I've tried copying the settings from that root port to all of the others, but I don't get anything anywhere else.

Does anyone know what root port the M.2 slot is connected to, and what settings I might have to tweak in the BIOS to make stuff appear?

Cheers,
R

[flyingfishfinger]

Quick update: An NVME drive works just fine....so now I'm totally lost. Clearly then the 4x PCIe lanes work, so why won't any other devices show up?

Fingers crossed for any group wisdom...

Cheers,
R