Fiora Ultimate Bug

I just played a match and 4 times when i ulted my ult did not land on the same person i ulted on . Yi , zed, karma twice. every time i ulted on one of them the ult wouldnt finish on them. i made sure i ulted after yi's q or zed's r . and karma is inexplainable. they were all in 5 man teamfights as well.