Persistent Bug- Seemingly just for me.

I've been consistently experiencing a serious bug in game for about a year now, but it seems like it only affects me. In about 3/4 of my games, I will randomly disconnect in the first 90 seconds. Always before 90 seconds. After I force quit and rejoin the game, it's not a problem until the next game. I've submitted countless bug reports, reinstalled my operating system, upgraded my operating system, uninstalled and reinstalled League, and played on four different wifi networks. The problem persists. Does anyone have any ideas how I can solve this? Thanks.