Low Tabs button dont work instinctively when multiple window open

Description of the bug: On second thought, its not that annoying just abit, but i'll still keep this post up

Pressing tab button to change tabs in eq/item/&other of such windows does not work instinctively when multiple windows are open
https://youtu.be/4o6RU2_ufbY
What is supposed to happen?: The last window that is clicked should act as the main window and respond to the tab/esc button.
Where did you find and/or notice this bug?: Everywhere ):
A step-by-step guide to re-producing this bug (optional):
Extra information (optional): Best explained with video :X sorry for my poor english. In the video, please notice how windows overlap other windows indicating there's a concept of "main window".