Possible game bug in group play

I notice extreme lag when there is a wizard using some frost spell, or a necromancer using a blood spell.

i can’t identify which specifically but happens every time, when I use Demon hunter dreadlands.

I dont know if its a bug, or whether it’s specific to me.

Any one else having this prob?

Update: I think it’s the necros freeze skill. It freezes me too, so i die . (Gear of dreadlands)

Definitely a bug