Solved Blank desktop folders but with icon images inside.

There was a time, in fact this was the situation on Monday of this week, that I had loads of folders on my desktop and they were all blank.
As in nobody could see what was in them, comes under privacy.
However inside of each of these folders were all large icons showing a preview of that image.
Loved this set up, what I don't want is preview images on my desktop as now is the case.

Fatal update this week Windows 11 Version 22H2 (OS Build 22621.1105).
Now it seems it is either or, why, and has anybody found a way to have the old combination, black desktop folders, with image icons inside?

Also why does a white line come and go now at the top of my screen please?

blank desktop folders

This situation of Microsoft changing something without the recourse of reverting back, I feel is misplaced and unguided.
Having blank folders is clean, preview panes add clutter.
The preview panes in themselves were not effective, only half a pane of the desktop folder, no way could you make them out.
In fact just this fact of them being half paned, tells you that the developer was having misgivings already.

But it is the potential lengths that one has to go to to revert back to plain blank folders, extraordinary - my experience:

1. To remove thumbnails on outside of folders in Windows 11 see here:
https://www.elevenforum.com/t/enable-or-disable...
2. In trying to enact a solution I was met by a half page warning sign, make sure you open it in full - Windows protected your PC
3. Click Run anyway, it did not run, but for me just clicking Run away resolved all my woes - unreal.