Kalista Bug or Malzhar Bug?

I just played a game where every time I went to ult (suppress) Kalista on malzhar, Kalista would do her knock back kite and break my ult. Is that suppose to happen? Seems broken if it is. I seem to notice a lot of people break out of my malzhar ult and it's to the point I don't even want to play him anymore. I could just be seeing things but the last game I played 3 people noticed it including the kalista.

Is this an animation bug or is there something in certain champions that if done at the right time breaks his suppression? I never see anyone break out of warwicks suppression only malzhars.

Note: no I don't move