Every time I try to reserve the edges of my screen, when I reserve a third edge, it reserves double the space that it's supposed to. So, instead of the edge of my maximized window being flush against the edge of my dock, it is twice as far away from the screen than it should be. Is this a common bug? Is there a fix for it? Any help at all?

It doesn't matter which order I reserve the edges of the screen in, the third edge always double-reserves. HELP!