Poppy bug (w does not prevent dashing)

I'm sure the W does prevent some dashes, however there are a few I have noticed it does not work on. I faced Hecarim in top lane, he was able to use his dash to escape out of my w, and into my w. I also happened to be facing an amumu, and throughout the game he too was able to dash to me, upon landing his Q. Again, this is when my W is active, which should prevent any and all sources of dashing from coming in. I understand "blinks" aren't included. However, these are not blinks, as you can see the champion moving in the case of Hecarim and Amumu. Upvote if you have experienced the same issue.