Tibbers bug

There is a bug with Tibbers. I play Annie a lot and noticed this a few days ago but did not think all that much of it until it kept happening. After ulting, Tibbers does not want to move when you click R to get him to move to tank a turret, attack minions, or different champs etc. He just stands there after clicking for him to move multiple times and then will move after about the 5th click or so. Did not happen every single time I ulted but more times than I wanted it to. Not being able to move him where you need him on time every few ults affects Annie's game play a lot.