Alistar Headbutt not hitting

I'm an Alistar "main" who's played him quite a bit through the past few years through all of the changes, I was just playing an Aram and noticed something I've never seen before with the champ.

1. I start a W headbutt toward the enemy anivia, she walls and it stops the W completely.
2. I start W toward enemy champs (multiple occasions) and they flash away as I am traveling toward them. I land where they were, no damage and no knock back applied and Ali didn't chase the flash with the headbutt as he has in previous headbutt attempts before this patch.

I'm not sure if this was ever supposed to happen and was fixed or if this is actually a bug but the headbutt was extremely frustrating to use as it was very different in its actions from the past.