I had already repaired and updated the game, then I went back into the game, but the original background was still there. you can only have one background at a time). So I put the background that I got tired of, in the 'Extra CAS Backgrounds' folder, and transfered a new one into the regular cas background folder (in the mods section. I had a cas background that I got tired of using, so I downloaded like 8-10 more and put them in a separate folder called 'Extra CAS Backgrounds' (which I did not put in the mods folder because it could cause issues in the game).
I have a similar problem but I'm not even sure how to fix it.