In that case something is off in the EFI Folder. I have long fallen into the habit where after every clean install or update, I run 'First Aid' on the Disk Volumes and check for errors.
The reason I included SecureBootModel is from personal experience where a few days after an update I was not seeing the message about the released update and was advised to check that setting and change it to Default as Disabled was the Default setting in the Sample.plist.
After making the change, reboot and clean NvRAM, the update notice showed up, so if SIP Integrity is on and SecureBootModel is Default, then I'll say it again, something is off on the system.
My machine runs near enough as a real Mac does.
Everything just works, the latest feature Handoff to iPhone Camera is 100% working flawless in F/Time (BTW 'Center Stage' is a blast where the Camera follows your head movement keeping you central on the screen), Camera Handoff in Photo Booth with added special effects some quite funny and Quick Time works as well as all the other Apple Services but I digress (trying to negate the blunt quote "Neither is true" response).