Why is it that this issue has not been solved.
I don't think there's any issue, I think you're confusing the movie poster
and the DVD cover
I've already explained it in my answers above, but let's repeat again...
Every time a movie is displayed inside a grid, what you see is the movie poster
which is the same for everyone and doesn't change even if you own DVDs of that movie. Theorically the movie poster should be a theatrical poster, but in practice it's common that all we could find is a DVD cover. Nonetheless, even when it's just a DVD cover, the picture that illustrates the movie is the same for everyone and doesn't change.
On the other end, the DVD cover
is displayed in only one place, which is inside the "owned videos" box.
If you get a wrong cover inside the "owned videos" box, please post a screenshot so I can check if it's a bug.