Question ASUS Maximus ix apex M.2_1 slot does not see kingston a400 240gb m.2 memory

[Husky88]

Hello,
I want to set two kingston a400 240gb m.2 modules in raid 1 but in advanced->onboard device configuration only sees M.2_2 and not M.2_1. If i exchange the two m.2 the M.2_1 is still the one not visible.
I'ts my first time doing this please help me.
Kind regards,
Daniele

 

[USAFRet]

From your user manual, page ix:
"M.2_1 supports PCIE mode only, M.2_2 supports PCIE x4 and SATA modes. "
https://dlcdnets.asus.com/pub/ASUS/mb/LGA1151/MAXIMUS_IX_APEX/E12404_MAXIMUS_IX_APEX_UM_V2_WEB.pdf

The Kingston A400 is a SATA drive.
The M_2.1 cannot use that drive.


What is the desire for the RAID 1? (even if it did work, which it can't)