Some tips from Sietse:
It usually happens after Cockpit has been opened on an external monitor. After disconnecting the monitor, Windows sometimes still thinks Cockpit should open on that now-nonexistent display. In your video, the brief white flashing animation appears to show Cockpit opening on this “virtual” external screen.
A workaround that consistently works for me is:
Open Cockpit, even though its window is not visible.
Open any other application.
Activate Windows’ split-screen function by dragging the visible application to the side or corner of the display.
aWindows should then show Cockpit as one of the available applications for the other half of the screen.
Select Cockpit.
Once Cockpit is visible again, close the second application and maximise Cockpit.
Cockpit should then return to the laptop’s main display and can be used normally again.
Some tips from Sietse: