Thanks. Executed
Get-AppxPackage Microsoft.SecHealthUI -AllUsers | Reset-AppxPackageand it worked. BTW, that line is the only place in the video that makes sense to me.
Yes, this is the only important part of this answer. It fixes the issue in less than a second and you don't even need to reboot your computer. Do this before you do anything like downloading Malwarebytes or running SFC because in most of the systems I've set up, Windows 11 does not install multiple necessary core components.