GA-Z170X-Gaming 7 (Rev 1.0) M2D_32G M.2 Slot Not Working

[Michael Milem]

I recently purchased a GA-Z170X-Gaming 7 (Rev 1.0) motherboard and I seem to be having an issue with the M2D_32G M.2 slot. I have 2x Samsung 960 Pro 1TB neither of which are detected when inserted into the M2D slot near the CPU. Both are detected on the M2H slot near the GPU. I've tried only having one of them at a time along with both at the same time. Both time only the bottom slot is detected. Under NVMe Configuration only the SSD in M2H is shown. Does anyone have advice as to what I should do to further troubleshoot the issue? I'm not trying to configure RAID either.

BIOS Settings:
Windows 8/10 Settings: ...WHQL
CSM: Enabled
Storage Boot: UEFI
Other PCI: UEFI

Motherboard: GA-Z170X-Gaming 7 (Rev 1.0)
BIOS: F20
CPU: i7 7600K
GPU: 1080 GTX
RAM: 32GB DDR4
SSD: 2x 960 Pro 1TB
No other HDD/SSD or any other SATA connections

[lapioks]

Did you try changing bios version? F20 bios has many bugs.

[Michael Milem]

Before I tried to downgrade down to F8 I selected 'Load Optimized Defaults' and it picked up the second one. Still continues to see both even after changing all the settings back to where it was. Strange.