On a multi-monitor system, the window appears on the wrong screen when restored from the taskbar. Steps to reproduce:

1. Use the simplest app:

#include <QApplication>
#include <QMainWindow>
int main(int argc, char *argv[])
{         
    QApplication a(argc, argv);         
    QMainWindow w;         
    w.show();         
    return a.exec(); 
}

2. Maximize the window

3. Drag the window to the other screen such that it remains maximized.

4. Minimize the window

5. Click on the button of the app on the taskbar to restore the window.

6.  The window appears on the screen where it was initially maximized and not on the screen where it was minimized.