ALliance Wrathgate quest chain bug

I am on the last quest of the Wrathgate chain "Finality" and I got the Phylactery from the dragon. I went back to Wintergarde, turned in, and got the next part of the quest to go talk to the troops inside the tunnel to the south. I went there, turned in the quest, and now the NPCs are standing around talking. There is no way to proceed, and it did not give me a follow-up quest. I do not have the Phylactery in my inventory, and no one has a quest or dialogue option.

I have disabled all addons, deleted cache and WTF, and I am still not having any luck. I am going to try one last thing and completely delete the interface folder along with cache and WTF to see if that sort of total wipe helps.

Any help or info is appreciated, thank you.

I did the same quest yesterday. Once you take the quest from the NPC and go inside the mausoleum firstly you'll need to wait for the lich's corpse to disappear if there is one. If the corpse is there you won't able to start the new part of the quest. Then you can start the quest to fight him - that part is bugged. You can do the quest except you won't be able to attack the lich. It should take about 10 minutes for NPCs to kill the lich alone, just stand there and you will get progress.