Weird lag on Sona on new map

I am not sure if this is a bug or not, but while playing Sona, when I first use Hymn of Valor, there will be a lock up of the game for about 1-3 seconds. It happens when I level Aria of Perseverance first, and come level 2, I select Hymn and go to use it to poke an enemy and then, game lock up. Again, unsure if this is a true bug or not, but considering that this has happened to me more than once, I figured I would bring it to light.