FPS drops after maintenance

I can't record the game because of how low the fps are but after today's maintenance each game with swain/rengar has been droping fps like crazy. From 80-100 normally to around 10-30 during team fights and 35 when farming alone in lane. I saw various players saying they were also affected by fps drops so that may be the case. It may be similar to the Predator boots bug when it was first released.