Sejuani W delay or cancel on champs running away when knocked up

I've noticed this start happening over the last week. If a champion is running away as you knock them up with sejuani's q, her w will have a massive delay and sometimes not go off at all. It used to be fluent and you could even auto reset before they hit the ground but now you can't even hit them once half the time. Also, I noticed if I hold down w while trying to hit them the on hit portion won't even go off, it won't even let me auto them.