It happens again and again. On two-monitor systems, Photoshop window hangs somehow just in the middle of them. Does it have any sense? I always close the main window when it's displayed on the secondary monitor. So why doesn't the program just remember its last position?
Since the top part is less then the bottom one, the system shows just a footer of the main window which doesn't have any control to recover. After clicking for some time to and fro, I finally unplug the external monitor and wait for Photoshop fits my laptop's screen. Then I plug-in the monitor again and move Photoshop back.
Until the next time I open it.
In general, any known algorithm to arrange windows across two monitors is a mess. The operation system, no matter if it's Windows, Linux or Mac, behaves quite as strange as it tries to compose some abstraction out from my windows. Some of them fly away and are shown partially. Other ones become tiny or huge. There is no any suitable way to return a window that flew away without suffering.