That systemboard, though reasonably new, is based on the Intel C612 chipset which only supports PCIe 2.0 (the systemboard itself does support PCIe 3.0 but not via the chipset) - while PCIe-based NVMe requires native PCIe 3.0 support - so the problem could well be that sorry.
That systemboard, though reasonably new, is based on the Intel C612 chipset which only supports PCIe 2.0 (the systemboard itself does support PCIe 3.0 but not via the chipset) - while PCIe-based NVMe requires native PCIe 3.0 support - so the problem could well be that sorry.