I think you misunderstood what I was trying to say. Left-click on the Firefox taskbar icon should maximize or minimize the browser with each click. It does work with Edge and Chrome, and it's working right now with Firefox and I just figured out why: It doesn't work when '''''Combine taskbar buttons''''' in the Taskbar Settings is set to '''''Always hide labels'''''. Setting it to '''''When taskbar is full''''' makes it work. Since it's no longer a problem, I'll mark it solved. Thanks for your response.