To reproduce (you’ll need a dual screen setup):
1- Import a video file into a clean project and press F8 to bring up the Video Window.
2- Move the video window to your secondary screen.
3- Right-click on the video and select Fullscreen mode.
4- Press F8 again (closes Video Window) and then move the time line.
5- Press F8 once more to bring the Video back.
You will see that the video window moved to the primary monitor instead of staying in the secondary monitor. If you exit fullscreen mode, the video goes back to its original screen. Can anyone confirm this?