Hecarim's ult not fearing

OK. So I sent a report to riot a few weeks back and I did get a reply . Ok so some times when ever I play Hecarim I notice that his ult does not always fear. This is really pissing me off and makes me not want to play him again because this is his only crowd control ability that he has. I am not able to record footage at the moment but if some one else encounters this bug please , if you can , post some footage.