Remember the days when you were running Windows, when a window would go off the screen. You lost control of it. You can’t move it. You can’t minimize or maximize it. All because the title bar is off the screen. Well, this happened to me today in Gnome. In Gnome! Can you believe it! Well, it’s a simple fix really.
Just hold down the Alt key and use the mouse to grab/move any part of the window!