Illaoi Ult Changed????

So I've noticed the last few games when playing Illaoi that if I have a target that is 1 hit from death and is also a vessel that, if I ult to snipe them with a spawning tentacle, the tentacle doesn't attack at increased ULT speed, it attacks at the slow reg speed. Is this a bug? They used to attack fast while the ULT was up but the last few games Ive noticed that isn't the case.