Pantheon Ult Bug?

Is it just me, or is Pantheon's ult incredibly unsynced to his circle, i've been seeing him a lot obviously and in multiple matches the time for his circle is SUPER WHACKY, sometimes it's the fully duration, sometimes it's just like 1 second, and on multiple occasions you don't see it AT ALL, he just APPEARS. I thought maybe the latter was just me, but my friends playing with me said they saw the same thing, and it's absolutely game-breaking to have a pantheon just appear out of nowhere and gank you/turn a fight, and you can't do anything because you have no idea it's coming.

Am I the only on noticing this?