Fiora blademaster proc

After trying out fiora and blademasters I started to feel that perhaps she's bugged. I see fiora proc her blademaster where she rapidly strikes and it literally seems to do nothing. No dmg, nothing.

Multiple times I've tried fiora with at least the 3 blademaster buff with items like guinsoos, IE and BT and she just seems to do no damage at all. Once I saw ww even dodge fiora and this is on top of seeing fiora proc blademaster multiple time and every single time it's underwhelming. I really think there is something wrong with fiora.