GNOME 3.30: Window overview cut off partially or window hidden completely from overview

[genodeftest]

Steps to reproduce:

1. have the latest version of this extension on GNOME shell 3.30. You may need to use GNOME/wayland, I am not sure about that.
2. enable this extension
3. open some windows
4. in GNOME shell, open window overview

What happens:
Some windows are cut off. Others are not visible at all.

What should happen:
Neiter.

Some examples:

Workaround:
Disable this extension.

[Rezzy-dev]

Can confirm this. Gnome Shell 3.22 -- exactly the same deal.

It seems to be rendering (visual memory) related. If the focus on the windows is changed forcing the system to redraw them, the preview thumbnails/images reappear. But if focus is shifted away from those windows again, the thumbnails/images disappear, leaving only a partial render or no render at all.

I suspect it has something to so with the shader being used (the implementation). With the shader in use, the available memory seems to be shorter (or it's somehow breaking/messing up the normal thumbnailing process, causing the overview to show partially rendered or unrendered thumbnails).

[Rezzy-dev]

I wonder if there's a way to tell the Gnome Shell to refresh its window preview images/thumbnails. Adding such a line to the program to execute after the effect changes have played out may be a good workaround this bug/problem.