Do you mean that if you open [press enter] the 'boot drive order' menu, still only one ssd is visible?
If it is visible when you open the menu, you may need to highlight it then use the + key to move it up in the order.
- key moves down.
Yup, it's missing from the 'boot drive order' menu. Just seeing one of my two identical ssd drives. One has Windows installed on it and the other Linux.
As you can see it shows up here under the SATA drives.
Both SSD drives appear under the F10 Boot menu. This is the only way I can select my boot drive and boot from it.
I was able to find a work around. If I go into the BIOS and switch to "Classic" view, and then change the Boot Priority settings from "Advanced" to "Normal", I can see all the drives. I was able to adjust the priority so that my formerly missing drive would boot first. Everything is fine now. Just wagging my head about how broken this BIOS is.
Hey good to hear you got it sorted! 
Yeah the mouse interface does not always show all the options available in the k/b interface.
But hang on, I'm confused here. Without a dual boot manager for win and linux, how were you going to select a boot drive without using F10 anyway? If you do have a boot manager, then drive order shouldn't matter - or does it??
I use grub2 as the dual boot manager. It installs stuff in the MBR of one of the drives and the rest are chained together through the grub config. It just so happened that the drive with grub in the MBR was the one that was not showing up in the BIOS boot order screen.
Thankfully, all is well now, but I sure wish Intel would fix this very bad user experience.
Dallas Clement wrote:
It just so happened that the drive with grub in the MBR was the one that was not showing up in the BIOS boot order screen.
Murphy moves in mysterious ways!! 
