Mordekaiser/Fiora bug

Ok so...I've been playing Mordekaiser top lane for a couple of weeks now. And I've noticed a reoccuring issue. Now since I've been playing Morde top I've been matched against Fiora about 5 times so far. And I believe I've decovered a bug with the interaction of Mordekaiser's Q and Fiora's parry. Now whenever Fiora uses her Parry when Morde has his Q active there is a case where it litterally stops Morde from doing any auto attack action. At first i thought that Fiora's W stuns, but then I asked a friend of mine as he said that Fiora's W only stuns if she parry's an ability that has CC on it. Now Mordekaiser doesn't have any form of CC. None what so ever, so there is no way that her W should be stunning him, but yet for some reason he stops attacking her completely. I can still move around but I can't use my other abilities either. So this is clearly a bug. Unfortunately I have no evidence of this, but my last Game as mordekaiser should be enough video evidence to see what's been happening. I've asked the Fiora in my game to meet me in top lane to test if her W was stunning or if Morde was just being buggy when hit by her ability. But the Jhin on her team felt like killing me while I was testing so I wasn't able to confirm. Please RIOT look into this.