I am trying to finish the Embers of Neltharion achievement and need the Symbol of Hope quest. However when I go to Alex in Val… she does not have the quest when I speak to her… I do not have it in my quest log either.
In addition, I read that she may spawn in Tyrhold for the quest… went there…nothing.
How can I get this quest?!? 
I am in the same boat and its actually the first quest in that questline. When I did a run print to see if it has been completed it shows true. The series of quest it shows that needs to be completed was A Creche Divided. Which is the very first quest to into the Embers os Neltharion patch.
I put in a ticket and hope for a response/resolution
ever time i try to talk to alexsrasza to complete the quest i dont get credit for talking to her to complete the quest not sure what it happening.
also If you have the Travel to Tyrhold quest abondon it and you can pick up the quest at the top of the tower, that is what i had to do