Too many people including me have this problem so it should be a bug. I wasted hours to figure out this,
There are 2 Dalarans. We do something and end up in the wrong Dalaran with a walkway in the middle. Instead of a portal room.
As Alliance go the Mages Portal Room and portal to Dalaran. This takes me to the wrong Dalaran,
But if I go to the Azsuna portal, then fly to Dalaran, I end up in the correct Dalaran with all The War Within quests.