Docking of "find usages" window issues..

>After few usages, I cannot get "Find Results" window into my view anymore.
>It has been same in previos version (80) as well.
>Is this a known issue?

well I am still experiencing this problem from time to time.
I am docking it on the right side and when pressing it's tab (only tab in the group),
it flickers quickly but nothing is shown, window just doesn't show up.