Lately I noticed that when I want to close or minimize a tab, or save a downloaded file, I have to click twice on the relevant button, instead of once like I used to. For example, this issue affects the three window control buttons on the top left of an open FF window; to close a tab, I would normally click once on the red (left most) button. But now I have to click it two times. The same for the blue save button which appears when I download a file; I have to click on it twice to activate it. It's pretty Does this represent a change in how the buttons work? How do I revert back to the earlier "click once" method? Or is this a new problem? This is FF 58.0.2 (also affected version 58.0.1), on a Mac running OSX 10.13.3.