Game Crashing

Dear Riot Employee,

From about 1-10 mins and sometimes in the last couple mins of a game my league in game client freezes and won't even let me move my mouse I am forced to restart or just close the league with task manager and reconnect to fix the problem for a few games. I've tried changing internet connectivity and redownloading league multiple times I don't know why this is happening I've been playing on this same comp since s5 on the same internet. The problems seem to only happen every 2-3 games. please let me know if there is any way you or I can fix this.

Thank You, Dashiel55