If a puzzle in blind mode ends with a pawn promotion move, the puzzle ends and resets without letting you know you solved it. You dont' get any info, such as what the puzzle was rated, or how many points you were awarded, it just seems to reset to the beginning.
It does award you the puzzle rating points however if the promotion is the correct last move.
You can avoid this behavior if you specify the piece to promote to instead of simply advancing the pawn.
For instance, in the following puzzle, enter the last move as h8=Q instead of simply h8, and the puzzle will finish as normal.
lichess.org/training/QKtOU
Happy puzzling.
It does award you the puzzle rating points however if the promotion is the correct last move.
You can avoid this behavior if you specify the piece to promote to instead of simply advancing the pawn.
For instance, in the following puzzle, enter the last move as h8=Q instead of simply h8, and the puzzle will finish as normal.
lichess.org/training/QKtOU
Happy puzzling.