Did you successfully complete the mission in which the game notified you of completing the challenge?

If so, did you claim the challenge from the Okri’s Challenges book?

There is a known issue with cosmetics randomly disappearing, and subsequently re-appearing for some players. We implemented a fix but it wasn’t robust enough - so we’re looking into it again.

Please be assured that your cosmetics haven’t been deleted. We’re working on it, and this will hopefully be resolved in one of our upcoming patches soon.

Apologies for the inconvenience in the mean time.