Riot what do I do?

I have been playing league without any problem for weeks now on this computer but the last passed 3 games I have played with my brother (GL SaBLe) I had my in game sound mute randomly and after I start lagging so I go to the ese game menu and disable all sound because the game sound randomly turn off in the beginning but it like freezes my whole game when I turn the in game sound off it only happened this patch so I dont know if its a bug with the patch or just my computer