I usually use a picture as a desktop and do not notice this, but I noticed a slight bright line on the right edge of my Dell XPS 13 with a wallpaper option. I confirmed by changing to a solid color (image above). When testing for light bleed this was not noticed because of the automatic screen brightness adjustment. In most cases I do not notice the issue, but I have to wonder if this is a defect or to be expected with this type of monitor. See a image with the browser at full screen to simulate normal use.
You can still see the ‘bright’ or ‘hot’ part of the screen on the right side, but it is not a huge issue. If you own a Dell XPS 13 9343; do you have this issue?