Stuttering, lag, fps drops

I have this persistent problem that sometimes fps drop under 60 (around 54 to 57). As this happens game is unplayable. Lag is so bad that you have to quit mid game.

This morning everything was fine. Then lag started. Reinstalled the whole game. It was playable for a few games and started again —> ragequit. Yesterday was the same story.

It is not internet issue, happens both offline and online. Constant 500 mbs. It is not also hardware issue, I should be able to play the game easily on medium settings.

Lowered everything, tried tweaking nvidia settings, power management, tried fullscreen and windowed, vsync on and off etc. Frames are capped to 60 fps.

Is this issue known and being worked on? Feel crap to pay for a game and get constant issues with performance. Or this there a workaround?