Question Pc doesn't see PCIe to SATA card

[Fusion_]

I recently bought another SSD to add to my collection. After plugging it in I found out that the SATA5 and SATA6 ports are disabled when using a M.2 NVMe SSD.
Alright, so this obviously sucks (as SATA1-4 already are in use) and I search the web for a solution. After searching for a bit I learn that you can buy a PCIe SATA adapter. This seemed like a good idea too me so I buy a Delock PCIe to SATA card.

Now to the actual problem.
My own PC doesn't see the Delock PCIe SATA card. Not in the BIOS, not in Windows devmgmt and not in Ubuntu's lspci.
The family computer downstairs does detect this card just fine (shows up in Windows devmgmt, but not in the BIOS).
I've tried all the free PCIe slots (except for the x16 and the one below it, because my 980Ti is slotted in the first and blocks the later with its heatsink/fans).
Now I read somewhere that this might have something to do with the amount of PCI lanes you have (but idk if this also applies to PCI Express), but I honestly don't know enough about that.

My pc specs:
CPU: Intel i7 6700k
Mobo: MSI Z170a Krait Gaming 3x
M.2 NVMe: Samsung 960 EVO 500GB
SATA 1-4: 2 HDD's and 2 Samsung Evo 850's
PCIe SATA card: Delock PCI Express Card > 2 x internal SATA 3 Gb/s + RAID (item no: 70137)

 

[alexoiu]

If removing the power cables from graphics card and using the onboard, does it work?

 

[Fusion_]

If removing the power cables from graphics card and using the onboard, does it work?

Windows wouldn't give me any display output, but on Linux and in the BIOS it still isn't detected. I suppose that rules out any possibility of a PCIe lanes problem.

 

[alexoiu]

Does the card come with a driver?

 

[Fusion_]

Does the card come with a driver?

Yes it does, but I didn't need them on the computer downstairs so I shouldn't need them here (identical windows versions).

I did manage to fix the issue. For some weird reason it only works when I plug it into the PCIe x8 slot (the slot meant for a second GPU). This unfortunately limits my main GPU to PCIe x8 but that shouldn't actually matter.