Lag but not internet problem

Hello, After the latest patch I have been getting frequnted lags in game but not in my internet my internet is running fine, never had this problem been playing since season 2... suddenly after the latest patch the game laags alot and I See alot of frame skipping and people jumping about and it happens quite often... and It's not from my end because my internet is fine, I speed tested it checked while the lag was occuring and was running perfectly fine, it's just in league of legends... please help