@voyageur1 Hey, Im not sure if this is a windows issue or an Opera issue, but the problem only occurs with Opera after the latest update to version 75.0.3969.149.
However this fixed it for me:
Hold down the Windows Key, then press “D“. Repeat these steps to see if it makes the window you are looking for reappear.
Alternately, you can right-click a blank area of the taskbar, then choose “Show the desktop“, then repeat.
this page might help: