Sion Voice Bug

So there's a bug with Sion that's been around since forever that for some reason he becomes very shy in the heat of battle. What I mean is, He loses his voice lines when he taunts, jokes, or laughs. I don't know what causes it, but it remains until he dies. Please fix this rito, it's not as fun playing a mute Sion when you can't hear his Emotes.