I have an idea
Currently background is set twice for two
divs, let’s try to set it once.
Please try to remove background from both widgets on that page and set it for whole widget area with this CSS code:
background-image: url("http://frantzimages.fr/wp-content/uploads/2016/02/wall-1074287_1920.jpg") !important;
background-position: center top;
Please remember about importance of regular backups.
Kind Regards, Roman.