Really unsure if this qualifies as a bug but before the new major update i used to get around 80 fps during laning that would drop to sometimes 50 during big team fights. After the update I am sitting at 65 fps during the laning phase without getting into big teamfights. Strangely enough i did not see major frame drops during teamfights (lowest it went to was 55) but there were times whilst farming and smaller fights where it would drop to 45 and such. This could just be an issue with my computer but the frames have gone down since the update.