Windows 10 just tried to force an update, even though I disabled that long ago

Please, let's not get into a fight about if I should/could/would leave automatic updates on. I prefer to update manually on my own terms, and many times I have something running that could need to run for several days at a time.

Anyway, so, I have Windows 10 Pro, and I disabled updates to it in two of the big ways recommended, by going into the group policy editor and disabling them there, and by editing the registry key "HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows\WindowsUpdate\AU" and setting the "AUOptions" key to 1 (Never check for updates).

And it worked for several months, while it used to nag me about every 2-3 days for updates before, it has been going for several months now without nagging me and letting me do the updates whenever I want.

But today, it suddenly tried to force them on me again. I came home to a full-screen popup that insisted I HAVE to install updates with the only option being to click accept. I assume this has something to do with the anniversary update, but I can't be sure. Has this happened to anyone else who disabled automatic updates? Or does anyone have any idea why it tried to do this and how to stop it?

InfoWorld > How to temporarily block the Windows 10 Anniversary Update version 1607 upgrade - by Woody Leonhard

Win10 Pro and Enterprise: Use the Defer updates option under Windows Update/Advanced Options. That typically puts off nonsecurity updates for about four weeks.

All versions: Set the Metered connection option under Network & Internet/Wi-Fi/Advanced options. Keep in mind, however, that this option is designed for wireless setups, it will delay security updates, and it can cause Internet-connected apps to not work properly.