FPS being weird

I used to play ow on 300fps low settings 100%render (borderless and fullscreen).
In the last week the game is acting weird,
the game is running 100fps not stable, and when on borderless it lags a lot (not fps)…
the fps counter at top left had 3 dots when usually had 1 dot (dont know what it means but heard it means stuff about rendering)
can someone help me please?
really being a nightmare playing the game

UPDATE: when I put it on VSync the dots are gone and works fine,but I don’t want VSync

Try these steps if you have not already:

It’s not one of the common issues like that, it happens to my friends too (10% of them)

I experienced weird FPS lags, was basically unplayable with my 144hz Monitor - So I checked the graphic details and maybe found the bug:
Graphic details were on ULTRA, even tho the expended settings where on medium as usual - put the main setting on medium and my game works again