Found myself stuck and couldn't find any options to boot from USB - no BIOS settings and boot manager was completely blank. Here's what fixed it:
Plug in at least one SATA disk (yes this is a ridiculous limitation) then go to Boot Manager (F11) and press enter on your SATA disk.
A menu then appears giving the option to select the USB drive.
Yes, this worked. I had to plug the USB in to the back of the computer, the front ports didn’t work for me.
Holy Toledo. Yeah, this works. Thanks.
Thank you very much!!!