To reproduce:
1. Open attached project
2. Open "scene". It contains a canvas with two images. One image is a raw image (texture), the other is a simple image (sprite), but their settings are identical
3. Notice that one of the images has a slight offset (a visible white line)

It seems that the offset is different depending on machine/resolution, as for me the offset is visible on the image, while the user it's the raw image that has the offset.

If you cannot see a white line try changing the size of the game view window and it will show up.