Kayn quotes missing? (gameplay)

I've been playing some Kayn lately and i've noticed a weird occurence that multiple people have had as well. It seems as though not all of his quotes are ''activated'' i suppose. He will repeat the same lines quite often and rarely do i ever hear a quote i haven't heard before. This struck me as weird since his VO is like 30 minutes long, while i've heard the same quotes twice in a row in game. So are they not activated or is it just me?