I need help

This is very rare but quite annoying. So when my game starts i get 0 fps and my ping is fine, a lot of attempting to reconnect.Every 30 seconds or so i get 10 fps for a second and the buttons i press will react only then. I tried closing league and reconnecting and trying to change my video settings. Nothing worked. If anyone knows how to fix this please comment.(i have 60 fps (fps lock) and no frame drops, ping constant 70-80, ram is 4gb cpu is fine)