Its missing.
I just ran a Game Review on a 960 game without issue.
For some reason i can't review this 960 game. (using the free daily one). I tried today aswell yesterday.
https://www.chess.com/game/daily/952137051
I haven't had any issues in review for standard or 960 until this specific game. (PC-web site)
Edit: by 30/04 still not solved.
Its missing.