What happens if the PCIe slot connector, that the AOC-SLG3-2M2 is installed into, can not be Bifurcated to x8?
If the slot connector is Bifurcated to a x2x2x2x2 configuration, then neither M.2-NVMe-SSD will be recognized by the system-BIOS. If the slot connector is Bifurcated to x8 or x16 configuration( if slot connector is PCIe x16), then only one M.2-NVMe-SSD will be recognized.
To have system-BIOS recognize both M.2-NVMe-SSD drives on the AOC, you must Bifurcate the slot connector to x4x4 configuration( or x4x4x4x4 if installed into a PCIe x16 slot-connector ). Be sure to check appropriate Motherboard User Manual for instructions on how to check/change PCIe slot connector Bifurcation