Game Engine Bug, Games does not PreLoad specific particle effects

For nearly 2 months now I have noticed that certain particle effects tied to champions cause immense lag upon their first use. This leads me to believe that the game engine is not preloading the effects. The problem with this is that the immense lag causes people to die, and happens across both teams. This is most noticeable when using any of Sona's powers for the first time. It is either what I mentioned above or some other issue. Regardless, it you were to take a look into the matter, Sona is your go to champion to see this in action. 100% of the time it happens. It is noticeable/happens universally to everyone in game. The effects are compounded when multiple abilities are used simultaneously for the first time, as often happens in early game skirmishes. I hope this is looked into and resolved.