Castling in Chess960

In your game with the black pieces (which is not the same as the posted screenshots), you did castle queen side on move 4.
https://www.chess.com/game/daily/633304291
In your game with the black pieces (which is not the same as the posted screenshots), you did castle queen side on move 4.
https://www.chess.com/game/daily/633304291
Help! Why can't I choose to castle queenside from this position in Chess960?