Supermicro X11 won't automatically boot

[BitCollider]

I've just recently built a FreeNAS machine using a Supermicro X11SSM-F motherboard. I have FreeNAS installed to a pair of USB Flash Drives. I'm having trouble getting the machine to automatically boot into FreeNAS on startup.

When I start up the machine (or restart it), I am dumped into the UEFI shell. If I disable the shell, I just end up at a screen telling me to insert a bootable disk and press a key. Pressing a key doesn't help. If I manually choose to boot from the USB Flash Drive using Boot Override in the Save & Exit tab of the BIOS, FreeNAS boots.

The BIOS seems to be configured to boot from the UEFI USB Key first, then USB Key second. (Screenshot attached.)

I've tried the USB Flash Drives in the USB 3 ports provided directly by the motherboard as well as USB 2 ports in the front panel of the case. I've also tried a different brand of USB drives. Same result in both cases.

UPDATE: Shortly after posting this, I became unable to boot into the USB drives at all. Selecting the drive from the Save & Exit, Boot Override section flashed a black screen briefly, then returned me to the Save & Exit screen.

What am I missing?

 

[BitCollider]

After discovering that I couldn't boot into the USB drives at all, I decided to try reinstalling FreeNAS to the drives from scratch. I found another flash drive, rewrote the FreeNAS ISO, and reinstalled across the two drives.

This seems to have worked--I haven't had any further problems and the machines boots immediately into FreeNAS. I'm still left wondering about what might have happened. Any ideas?

 

[SweetAndLow]

Your bios or boot devices must have been goofed up. Usually that doesn't happen.

 

[joeschmuck]

I would highly recommend that you change your boot order from "DUAL" to "LEGACY" and that will eliminate all that UEFI crap which can and does cause issues. I have been much happier after doing that on my X11 board.