Mokutil fails to disable validation

When using the command "sudo mokutil --disable-validation", I am asked for my system password and then asked to type a separate password twice, but then receive the error "Failed to request new MokSB state". When the system is rebooted, it does not ask for the password and validation remains enabled.

I cannot therefore use things like Nvidia drivers or Virtualbox without disabling secure boot in the UEFI BIOS, which I don't want to do as I also use Windows 10.

The various prompts to disable verification elsewhere in Ubuntu (e.g. during setup and in the Additional Drivers menu) also fail to disable verification. This can result in the user unexpectedly being unable to log in after installation of Nvidia drivers, which is very user unfriendly.

Possible solutions: (i) an alternative way of disabling validation, (ii) option to install ubuntu without verification capability to begin with, (iii) common things such as Nvidia drivers get automatically signed so that they work with secure boot, (iv) more detailed error messages from Mokutil.

I suspect that my motherboard is refusing to create the required variables.
Ubuntu version:
16.04

My hardware:
Motherboard: Asus Z97 Sabertooth Mark 2
UEFI BIOS version: 2601.