It has happened to me several times, also.
To bring a hidden or off-screen window back to your main desktop, you can use keyboard shortcuts or taskbar options.?Right-click on the taskbar and select "Cascade windows" or "Show windows stacked" to arrange open windows, including the hidden one.?Alternatively, use Alt+Tab to cycle through open windows until the hidden one is active, then use Shift+Right-click on its taskbar icon and select "Move" to reposition it using arrow keys,
Walt W0CP