Anivia Bug

I was just playing an Anivia game. In that game there was an enemy blitz , if I got pulled when I had my ult out his pull would cancel my ult. I know that there is a distance to when her ult cancels itself, but in this case I was pulled into where my ult was. Just thought I'd let you know since it makes Anivia's ult go on cooldown also. Thank you.