[gameplay] keyboard disconnections mid-game (every few games)

My keyboard gets disconnected every other game or so, afterward nothing works (including alt-tab and such) and I am forced to restart the pc and reconnect to the game. As I've said, it happens every other game or so, seems like mostly while I'm inactive with the keyboard for a few seconds (running from base to lane, after death etc.), I haven't found a more specific cause to the bug. I've read in forums that it is a common problem and despite resetting the config file and re-downloading the game, the bug persists. (which are the usual answers to similar problems). Thank you in advance for your help, your's truly, a random summoner.

*this only happens in league, not while using the pc in any other way including many other games I play.

info: my pc is a Lenovo IdeaPad y700 with a 960m Nvidia GTX graphics card and an intel i7 core processor. playing in the Europe Nordic and east region, the bug has been around for a few months now.