Nocturne Shroud of Darkness(W) is not working.

Played a normal match on the twisted treeline, the other team said they never witnessed me cast shroud at all during the game, but i cast it once or twice every fight/ duel(more than a dozen times). In total it only countered one enemy ability all game after that first counter it completely stopped working. I could see it cast on my screen but the CC ability would still effect me. The other team could not see any visual of me casting it all game.