Resolved Can't Boot From USB

I am trying to do a fresh install of Windows 10 on a HP laptop using a bootable flash drive which I have used several time in the past. I can enter the BIOS and reset the boot order with USB Flash Drive/USB Hard Drive option first. When I save and exit, it boots into the operating system . Here is what I see on the BIOS Boot Options Tab:
UEFI Boot Order
USB Flash Drive/USB Hard Drive
Internal CD/DVD Rom Drive
USB CD/DVD ROM Drive
Network Adapter
> OS Boot Manager
No matter which one I put at the top of the order, the machine always boots into the operating system as though it's not recognizing which boot option is listed at the top. I'm sure I'm missing something obvious but I don't know what. Any ideas?

 

When you are in the operationg system, what happens when you plug in the flash drive? Does it see it?

 

Yes. And I can see the list of files that are on the flash drive.

 

Thanks Mr. Bill and Tony. It's installing right now. Apparently the boot sequence in the BIOS is different from the one that I was able to access using Tony's instructions. Bottom line - WindowsBBS came through again.