And while you check on Fast Boot, please also look at #5 here: USB boot install
Although from my anecdotal experience, it seems Secure Boot (which you already took care of) and Fast Boot are the typical culprits.
And while you check on Fast Boot, please also look at #5 here: USB boot install
Although from my anecdotal experience, it seems Secure Boot (which you already took care of) and Fast Boot are the typical culprits.