saguaros Hi Saguaros, unfortunately the problem persists.
To help you and your PC colleagues see the problem I've changed all the slideshow images to black. The vertical line is now more visible than ever.
I also recorded two small videos showing my experience (via Windows 'Snipping Tool'), but this forum's platform didn't allow me to upload this video type. Maybe the black slideshow-images will be helpful enough for your PC colleagues to see the problem, if not, we can figure out how to upload/show you guys the videos of my experience.
Lastly, here are some additional comments upon investigating this issue further:
1) As the line flickers it also disappears in certain points allowing one to recognize the line does not emcompass the whole image, it only appears on the left side of each image.
2) Though the line seems to appear between the slideshow images, it's actually above all the further most (1px) vertical pixels on the left side of each image.
Hope that helps. Let me know if you need any more info.