KB5015818: Release Preview Update for Windows 11 v 22H2 Build 22621.232

Update: It didn't work, it said settings are unavailable right now or something along those lines.

I don't think Microsoft can say they don't know about this problem. From Feedback Hub:

I will try this rn

So...delete this whole folder? Also I have not seen the update in my history unless it was in my un/reinstall W11 phase.

Check if you have this folder 1.0.2109.27002-0 in SecurityHealth. If it is there you can delete it with all its contents and the problem will be fixed.

C:\Windows\System32\SecurityHealth\1.0.2109.27002-0

Note that it requires system authorization to delete.

You can use command prompt from recovery mode.

I used the command rmdir <path> /s to delete the folder and all its contents.

rmdir | Microsoft Docs

Also, you probably miss App & browser control, the 2 problems occur together when that folder is present. ...

Deleting that folder fixed the bug on all 3 machines.

The machines that did not have the problem showed

C:\Windows\System32\SecurityHealth\

empty with nothing in it.

Yes, that was one heck of a valuable contribution on your part, fg2001. And it only begs the question, why does Microsoft think it is acceptable for them, to cause widespread frustration among the users, for such inexcusably long periods of time? You even did the work for them, free of charge! How hard can it be to get that fix distributed along with the frequent Defender updates?