Changing views, or as I just did, clicking on "Attribute" to find a photo, sometimes pops up another window, a second "Secondary Display" window. I then close that window which, of course, closes my Secondary Display, and I have to reopen it. Daily!
That time I was in a folder deleting photos marked "rejected", and Blooey! A second Secondary Display window appears (on my first monitor), and the selected photo jumps to the first photo in that folder (by Capture Date). Second time in an hour! @#%&#!