preview of selected miniature in taskbar not displayed

when hovering over a miniature in the taskbar, normally, and waiting for an instance, a full screen preview is displayed of the selected miniature.
However, since a day or two, this is not the case anymore.
Anyone has an idea why not?

Hello Koen, and welcome to Eight Forums.

Usually when you hover on an icon on the taskbar that has an open window, you will see it's "taskbar thumbnail preview". If you hover over the taskbar thumbnail preview, you would then see the "taskbar thumbnail live preview". The taskbar thumbnail live preview is quick peek of the actual main window.

If you are no longer seeing the "taskbar thumbnail live preview" when hovering on the "taskbar thumbnail preview", then you could do a system restore using a restore point dated before this started since it's only been a day or two. This will hopefully fix this quickly for you without any issues.

Hope this helps,
Shawn