Yi's Alpha interrupts Taric's new Ult Channel [Gameplay] Bug

Today in Patch 6.8 has something very strange happened. The new TARIC channeling its Ultimate and after 2.5sec when everyone invincible in radius is Master Yi in Alpha Strike. In the pictures you can see with the TARIC Ult down in the bar and at the same moment Master Yi without Ult in the bar. Before he made Q he stood beside Vayne, which was bounded with TARIC and had his Ult. The bug is very clear for any questions feel free to join the discussion. This is adjustable as well in custom, but it is not when Master Yi is connected to TARIC and then gets ulted. https://www.youtube.com/watch?v=sSZq43VwGYc