ASUS BIOS keeps resetting Boot priority to Windows Boot Manager before UEFI

I have gone into F2 BIOS settings and saved

Boot Option #1    [UEFI: SanDisk]
Boot Option #2    [Windows Boot Manager]

However upon rebooting the system (Win10) goes straight to the hard disk Windoze10 installation without accessing the USB drive.

Here is screenshot that the BIOS has automatically reset to the Windows Boot Manager first again.

I had already tested this USB on this same system and it had booted in the past. No idea why this new (and totally frustrating!) behavior is occurring.

Anyone else with knowledge/fix for this..

Update I see this Boot Override in the Save & Exit. It is not configurable. Is this relevant? If so , how to remove the override?

Answer

After more digging found one answer here that is working.

http://www.tomsguide.com/answers/id-1973164/change-asus-boot-order.html

I just completed a CHAT session with ASUS. It worked!! Here is what they told me:

1. Enter the BIOS setup menu by pressing and holding F2 key when powering on.


2. Switch to “Boot” and set “Launch CSM” to Enabled.


3. Switch to “Security” and set “Secure Boot Control” to Disabled.


4. Press F10 to save and exit.


5. Press and hold ESC key to launch boot menu when the Unit restarts.

We now get the following (happy!) screen:

And we can get to the Ubuntu Boot Disk:

(* 20 mins pass *) And now I am logged in and editing this question from the (successfully) installed ubuntu 15.10 woot!