Kerrigan's Ultralisk bug

As the title says, kerrigan’s ultralisk has a really annoying bug that really needs to be fixed. Basically during the 0.5 when kerrigan is channeling, if she get stunned or knocked back or something else, ultralisk spawn on kerrigan position, instead of going like every other skill on those 9 cd seconds. This bug was here for a long time, i would like if it get fixed.