Board Thread:General Discussion/@comment-37653663-20200409104807/@comment-3026053-20200409112010

When you go to the theme designer and look at the background tab, you have two options underneath the graphic image, the left one is "tile", which causes your images to show up in tiles like you're experiencing and the other one is "fix", which locks the background to the sides and makes sure that it doesn't disappear when the viewer is scrolling down. I don't know how the option would be named in French, but if you deselect that left option and possibly select the right, your issue should be resolved.