Winform -Dual monitor - Borderless Window -is maximized only to primary screen size

Question

I have a problem with multimonitor system and maximizing my borderless C# Winform window. I'd like the form cover two screens, but it only cover the primary screen.

        Screen[] screens = Screen.AllScreens;    
        int height = 0;
        int width = 0;
        foreach (Screen screen in screens)
        {
            //take smallest height
            height = (screen.Bounds.Height >= height) ? screen.Bounds.Height : height;
            width += screen.Bounds.Width;
        }

        Size = new System.Drawing.Size(width, height);

        WindowState = FormWindowState.Maximized;
        FormBorderStyle = FormBorderStyle.None;