by Aivars » Fri Nov 06, 2015 2:27 pm
Ok I managed to get it finally. I figured out that you maximize by doubleclicking title bar, and the issue is that Taskbar (tab bar) registers the doubleclick, too, if the position of restored window is just right. Since doubleclicking Taskbar opens new tab, that's what happens here. I'll add it to bugs list but I think it's a low priority bug.
Blumentals Software Programmer