[In Game] Minor screen freeze during early game

• not since this patch, have been constantly getting these this season
• happen only in early game, someone on my screen casts some spell (could be any, not only due to specific champion or spell) and my screen just freezes for a moment, this would happen a few times and then things go back to normal for the rest of the game.
• boarderless, 2560x1080, very high, vsynch on
• i5-4690, gtx 960, 16g ram, windows 10

Really bothersome for my laning phase