I'm trying to get two separate wallpapers for my two monitor set up. I've installed nitrogen which I heard is able to do this. However when I press apply in the nitrogen GUI nothing happens on my screens and the old wallpaper is left up. When I log out I can briefly see the wallpaper set up I designed with nitrogen but then it goes back to the old wallpaper. I feel like something is overriding the nitrogen settings. Any help with how to change this will be greatly appreciated. Thank you.