System SSD is plugged into SATA port 0 according to BIOS yet the physical port 0 is not occupied

[pooeee]

I have a main SSD drive which the operating system is stored on. It is attached directly to the motherboard and is listed in BIOS as being plugged into SATA port 0. The motherboard has 6 regular SATA ports that all have hard drives plugged into them. They are numbered 0-5, therefore the hard drive which is plugged into port 0 isn't recognized. It is powered on, functioning normally (tested on a different PC) and the SATA cable is brand new. It looks like the SSD is occupying port 0 despite not actually being plugged into port 0. Any ideas how to solve this? Thank you.

Specs:
Windows 10 Pro 64-bit
Intel i7 8700 @ 4.6GHz
32GB Crucial DDR4
Gigabyte Z370M D3H-CF
NVIDIA Quadro P400

 

[DRagor]

What SSD is that and where it is connected to motherboard?

 

[rocktalkrock]

If a Sata SSD is plugged into the first M.2 slot (M2A_32G) then SATA port 0 (SATA3 0) will be disabled.

 

[pooeee]

If a Sata SSD is plugged into the first M.2 slot (M2A_32G) then SATA port 0 (SATA3 0) will be disabled.

Right, of course that's it. I checked closer and I can see the "M2A_32G" label next to the SSD. Is there any way to enable the port or do I have to add more SATA ports if I want to connect all my shit?

 

[rocktalkrock]

If a Sata SSD is plugged into the first M.2 slot (M2A_32G) then SATA port 0 (SATA3 0) will be disabled.

Right, of course that's it. I checked closer and I can see the "M2A_32G" label next to the SSD. Is there any way to enable the port or do I have to add more SATA ports if I want to connect all my shit?

The motherboard is limited to 6 Sata devices, no matter how they are connected, Sata ports or M.2. The only way to add more Sata ports is with an add-on PCIe controller card.