Yes, it was for me too last night. Makes me wonder if people killing the mobs outside of the ring before they get into the area keeps some sort of activation from occurring that clues the game in.
Same for me, second day experiencing this bug and cannot proceed. Submitted a bug report but due to time constraints I can't sit and wait for GM assistance, if they even can help.
I was given this solution when I got stuck and it worked. When you get to Survive the Anger of the Undead, log out to the character screen and wait for at least 30 seconds. Log back in and try again. You may log in to a different instance where the quest does work. I tried it and was able to successfully proceed.
IGN: Adhamh
Race: Nord
Class: Dragonknight
Alliance: Ebonheart Pact