@nunya Thanks for your reply! Following your suggestion, I've checked what happens in the "preferences" file and found that the horizontal "window_placement" parameter is 0 when the window is positioned at about 20 pixels or so to the right of the left edge of the screen. If I leave it any closer to the edge, the value becomes negative, and when Opera is restarted, the window is repositioned at that minimum distance (curiously, the value in the preferences file remains negative). If I indent the window by more than 20 pixels, the value in preferences reflects the correct position and the placement is kept between restarts. I have also noticed that the placement values seem to be expressed in 1080p-sized pixels, even though I have a 4K screen, but that, I think, is still a common practice in software design. What I don't understand is why Opera would regard window positions that are too close to the left edge as negative...
