Fiora vs Fiora Bug

Just got out of a game where i was play a mirror fiora match up and we were trading back in forth at level 4. I Lunged at the vital and she riposted it and after that for the rest of the time we were trading no other vitals would show. I don't know if this is just a dumb mechanic that I didn't know about or if it was actually glitching. I've had multiple problems with her passive not occurring at all when I'm near someone and I am visible to them. Sadly I didn't have the match recorded but if I get it recorded I will add a link to it.