Green Maximize Button

I actually like how the button usually maximizes the window just enough to prevent horizontal scrolling, but recently this has become very inconsistent. When I press the button in firefox right now, the window gets extremely tiny, almost just displaying the red, orange and green buttons. When I press the green button again, the window goes full screen. Is there a way to reset window behavior so pressing it only sizes it perfectly instead of stretching the page to widescreen?

Thanks

 

Haha I feel so silly now! I thought there would be a button to reset the screen size! This is easy