It's nothing new that Fioras W is bugged
Her Riposte is really bugged because her animation is clearly shows i get stunned next to her. On another note, she is free to auto attack an enemy even though the animation of her W still stands so as in the clip she attacks the vital. I always saved screenshots and videos of me being stunned next to Fioras W or getting stunned even though her animation is done or in other words Fiora Riposts by moving forward with a sword and even though she puts down the sword after finishing, the indicators still stand therefore would stun you no matter what. My point is that her despite stunning the person next to her is that her body animation to indicators is not on the same 'time interval' or however you want to call it which allows Fiora to auto attack in between the animations as presented.