Do you use greater than 100% for Windows settings: Display: Scale and Layout? I use 125% to improve the readability of my screen, and when I maximize a popup window (e.g., attribute table) it seems to size the window to the original screen resolution without taking into account the Windows Scale setting. I use a two-display setup that's extended, as well, and when I have the popup on the right-hand monitor it orients well to the right of the left hand edge. I hypothesize that it's orienting the top-left to (y-resolution + 1) but because I'm at 125% the y-resolution of the first monitor is 20% smaller.