Multiple solution puzzle

So, i was doing puzzles when I got this one: lichess.org/training/Esolm I played the two first moves right which are Ra2+ and Kg3 and the after white played Kf1 avoiding mate, I played Ra1+ which is winning according to stockfish, but the puzzle gave it as wrong. The puzzle gives f3 as a solution that is also winning. Both solutions are correct but the puzzle just gives one as correct.

If you look at the lines, at depth 36 you'll see that f3 is -58.8 in favour of black, while Ra1+ is only -8.3 in favour of black.

By move 70, the first line has you about to get a queen after having traded rooks. The second line has you winning a rook but losing your pawn/queen, and still having to deal with white's remaining pawn. One is clearly the better line, and puzzles require you to find the best move, not any move.

I think puzzles must have just one solution. Anyways -8.3 is an advantage in which black should be able to win without any trouble. It is true that f3 is an easier win than Ra1+ but both are right

Hello, thanks for the report puzzle will be deleted, in the meantime it will not be shown to other players (except by direct URL).

I agree, it's a bad puzzle.

One can argue that one move is *more* winning than another, but as long as both ways easily leads to a win, it should not be a mistake to choose a more slow way to win. It's like fail a puzzle where you have found mate in 4 while the fastest is mate in 2. Or when in a solved endgame you chose a simpler (for you), but longer way to win (google for "Magnus takes 100 endgames test" for an example).

Thanks guys.