Harmony of Despair drops below 60 fps in certain levels

I recently setup Castlevania Harmony of Despair for the RPCS3 emulator which works great ! The only slight hiccup is that the framerate will go from 60 to about 42 fps at the start of most levels (killing a lot of entities on a map does improve the fps). Now the game does not lag or slow down at any point, it's only lower framerate but I do wonder if there is a way to fix it and make it constant 60 fps. I've tried quite a few settings but the result is always the same (even with minimal resolution). I very highly doubt that my computer is too blame for this as it is well above the recommended requirements. Perhaps that is how the game originally operates but I have seen posts of people claiming that they are able to pay it on RPCS3 at a constant 60 fps. Does anyone have any suggestions ?