Miss fortune ult

I was playing adc in the pre-season of ranked and I chose kog' maw and the other team chose mf so we get in game i get 2 kills before level 6 and when mf hits 6 she starts winning lane but she didn't ult. It wasnt that she didn't ult it just that I could not see her ult it could of been 1 game thing, but another game i was top lane and the other team chose mf and our adc couldn't see her ult either so, it might be a visual glitch when laning against her. If anyone else has experienced this tell me in the comments please and thank you :)