I once disabled this feature and as far as I can recall, it was somewhere in kwin's or in Compositor's Setting, but I'm totally blank now and don't remember how I actually did it before.
What I'm talking about is this, below
I don't like this as I totally lose track of the window I'm currently working on, and if the count of instances is greater than 10 then its very difficult to pick the correct one. I recently updated my system and since then I'm getting this, instead of getting a list of open windows.
Thanks in advance
kcmshell5 kwineffects
. Ignore any terminal output and maximize the window that appears. Scroll to "Window Management" and turn off "Present Windows". Click "Apply" in the lower right corner. Close the window. – DK Bose Jun 13 '20 at 13:11