SATA M-key adapter not recognised by X86J4105

I am building a NAS and have antadapter for additional SATA connectivity. I have tried other boards in the PCIE slot and they all work and I have tried using the adapter in a different computer and it works fine. The adapter board I am using does not show up in bios at all.
Any help as to what is happening would be appreciated.

@Ian_Oxborrow The M key(PCIE2.0x4) is near the wifi module and B key(only sata signal and USB 2.0) is near the sata port. The adapter you showed should be worked with M key.
Confirm the adapter is put into M key?