As if instead of being a penalty specialist as claimed visually by the game, he is a penalty failure specialist.
The same applies to those 6-7 stars GK with special abilities.
I had a player (AML/ML/DML) that was supposed to be free-kick specialist, but I think he never scored from a free-kick in 2 seasons or so.
But, I had players that appeared to be good or at least decent in what they are supposed to be specialist. I had also an MC which was a free-kick specialist; he was scoring from almost every free-kick he took.
So, briefly, in other words, the special ability only works when the game wants it to appear as if it has worked or there is something in this game that regulates the efficiency of special abilities also.