2nd time i've lost in Fischer Random because the dumb 0-0 castling is completely illogical (illegal)

Can someone explain why this doesn't work because I know castling is the same positions as normal chess so black castling here 0-0 would be legal because king would go to g8 and the rook would stay in place on the F file on f8?!??! This is the second time i've tried castling short as black and it just doesn't work... is this bugged? can you only long castle as black? idk frustrating though...

nothing is blocking the castle either, so im not castling through check here....

Do you have a link to the game? I don't see a recent 960 game.

Actually, found it on the Variants server and tested. You should be able to drag the king onto the rook to make it work. Not sure why you can't drag the king to the destination square on there.

Cuz the destination is not there, the rook and king will change places