Sometimes, in Windows 10/11, an application's window can get "stuck" off-screen, and cannot be moved.
The following steps can be used to move the window back to the screen:
- Activate the window in the task bar
- Press
Alt+Spaceto open the window's menu - Press
M - Press
Enter - If necessary, use the arrow keys to move the window
(Thanks to user barlop on StackExchange)