Top panel space overlays fullscreen in Games
Something that bothers not only the space of the top panel of the gnome shell, but also because the mapping of the cursor location changes. The (full) game screen is pushed down through the top panel space. Applying another screen mode and returning to full screen temporarily solves the problem. but just toggle the windows with ALT + TAB, that problem returns instantly. It is worth mentioning that the problem occurs with most Games in OpenGL. Examples: Counter Strike Global Offensive and Rocket League (tested).