Incorrect puzzle: at least 2 solutions

I tried to solve lichess.org/training/ObN7x
and played a6 and lichess says the move is wrong.
According to deeper engine analysis a6 is (at least) as strong as h7.

@StehtWieNeEins said in #1:
> I tried to solve lichess.org/training/ObN7x
> and played a6 and lichess says the move is wrong.
> According to deeper engine analysis a6 is (at least) as strong as h7

You see, if i do a7
The black rook will come behind the a pawn and the white rook will also come and then after blacks move we will get to play h7, so this is quite long