In an attempt to add a default background to Nintendo Entertainment System games that didn't have their own fanart backgrounds, I figured out that I could add a file named LaunchBox\Images\Platforms\Nintendo Entertainment System\Fanart\Nintendo Entertainment System-01. This works, and now games with their own fanart have their own backgrounds, and games that do not, use the one I added.
Everything is great, except, before on the main menu, I would get a random fanart background when I would stop on Nintendo Entertainment System. I really liked that. Now, I get the default background that I added every time. I'm hoping there is something that I'm missing here. Is there a way to do what I'm trying to do? Thanks so much for any advice.