Warwick ult bug

There is a bug in my last game i came across involving Jayce and his knock back on Warwicks ult. In the play where i noticed the bug, I was running at jayce he was in his hammer form i ulted and connected and during my ult, not right when my ult connected, jayce knocked me away. Now warwicks ult is a suppression so there could be a bug with the suppression that allowed him to knock me away during my ult. Or another cause if jayce buffered his hammer knock back ability which should have worked because wws ult cannot be interrupted, unless they changed that and i missed it in the patch notes. if jayce buffered his knock back it would have tried to hit me in mid air which did not happen.