While setting up an Unraid NAS Server for file storage and virtual machine hosting I found that the USB drive was not showing up in the UEFI BIOS Boot Priority drop downs. This was confusing because when I manually selected the boot with F12 the USB device showed up.
I found a helpful reddit post on the subject here
Steps
Use F2 to enter the UEFI BIOS and select the Boot menu
Then select the “File Browser Add Boot Option” and follow the GIF below
Select the USB drive, then EFI, boot and then bootx64.efi
It will then prompt you to name it, for me I used “unraid”. This is the name that will show up in the boot priority dropdowns
re-arrange boot priorities by first moving the Windows Boot Manager to the #2 slot then add unraid to the #1 slot
The UEFI BIOS can freeze during ordering so make sure to move windows boot first then assign unraid to the top slot.
Now once you restart, the OS on your USB boot drive should boot first instead of windows.
