That's what happened for me
Mine used to change every time I leveled up in my career and suddenly it stopped changing them period. I talked to someone from EA and they said my game might have a bug, but they didn't tell me how to fix it.
If you're using cc, try removing that. Otherwise, try repairing the game through Origin
I'm not sure what cc is, and I don't know how to repair it through origin. They were the ones who told me I might have a bug and sent me to some Forum.
CC = Custom content you download from third party sites
Repairing: Right click on the game in Origin and hit repair game
