[Gameplay] Fiddle's Q is delayed on cast

In the last two games I've had Fiddlesticks, his Q has had about a one to two second delay before it takes effect. For instance, I cast my Q on a riven, and she was able to use her Q two more times before she was feared. Most recently, I cast the fear on a Garen, but he was able to chase me for a bit, basic attack me, and THEN the fear finally went into effect. There is no delay described in the skill description, so is it supposed to be delayed or is it a bug?