Earthshatter particles progressively drop FPS by not being removed from the game properly

When you explode earthshatter spikes with a warcry, theres a lot of particles being generated. These particles visually disappear over time, but apparently are not removed from the game and still put a load on GPU. As you explode more spikes in the same spot, GPU frametime in built-in monitoring tool increases more and more, FPS drops progressively.
So apparently these invisible particles are never removed from the area until reset. If you move away from the spot where you used earthshatter so it is not on the screen, FPS goes back to normal, return to the spot with invisible particles - FPS drops again.
This is a problem during long fights in small areas. For example, during Trialmaster fight my FPS gradually dropped from around 85 in the beginning to 38 towards the end because of accumulated invisible particles from earthshatter.