Used last night but didn't hold and wasn't on my buff list. Edit: No, my buff window wasn't full just in case someone mentions this.
Did you receive a "blocked by" message in chat window? Did you try casting it multiple times and it kept failing?
If it didn't land on you then you either had something blocking it (such as a potion, even if it wasn't you that used one) or you were buff locked. You'll have to post a video of you trying to cast it to prove otherwise.