I don't know if it's M.2 or not, but I did physically removed the SSD from the motherboard and booted with the Windows Flash Drive to test with cmd's diskpart, apparently even when the SSD is gone, diskpart only recognized one drive: the bootable usb drive itself.
I did enter the BIOS and RAID mode was not an option in the SATA controller, it was either AHCI, RST Optane or RST Optane premium.
I did enter the BIOS and RAID mode was not an option in the SATA controller, it was either AHCI, RST Optane or RST Optane premium.