Can't get certain accessory off sim

This sim I recently made has this weird medal on when wearing alethic clothes. It was already there when I made her. I used the randomize button to create her and then I changed some outfits but I cannot get this medal off.
I tried equipping other stuff, which at one point it should take it off, but it didn't work. It's not visible in her outfits or accessories.

Picture:
https://mrmlsims.tumblr.com/post/683166232526127104