trynd ult broke

I have seen on many posts already that different champs are cancelling his ult. I too have experienced this except with Voli he ults I ult he kills me as soon as my hp hits 0 while my ult is still active. Ive seen others report this about fiora as well and another champ that I didn't see. Plz fix this rito trynd is one of my favorite champs.