One thing you can try while booted up is to run 'mokutil --set-verbosity true' and then reboot, to see if you get any output on the screen from shim that would let us narrow down where things are failing.
One thing you can try while booted up is to run 'mokutil --set-verbosity true' and then reboot, to see if you get any output on the screen from shim that would let us narrow down where things are failing.