Champion select lag

So i have a little big problem right here, I am running league of legends on a pc with some pretty good specs (i7 6700k, gtx 750) and i lag in champion select. It is frustrating, i have this problem since season 9 or so, i can't even make my rune page and this time i couldn't even pick my champion and pick it. The fact that the client lags so much keeps me playing other games. I don't think that there's a problem with my pc tho, i run GTA V, FiveM, Rainbow Six Siege, CS GO with no problems and i can't run a damn league of legends? I don't think the internet is the problem since i don't lose a package and i have 30 ms constantly so riot please fix this bug instead of adding lux skins like come on i can't even play