Blowing the horn for Vethir to close the portals does not work. I receive orbs. This is in Legion remix on a level 80 demon hunter.
I did this quest not long ago, and it worked then. Top suggestion in wowhead seems to be to use the horn in the bag, not in the quest tracker. I don’t recall it being an issue though, are you sure you are in front of the portal?
Community > Legion Remix or Gameplay > Quests would be ideal for these type of questions in the future.
What are you using? What shows up on the screen as the special action button? If so, that is not the right thing. That is to help kill the mobs around the area because they were a lot harder back in the day.
You need to either use the horn from your bag.
Thank you Kozzae and Aryalkanthu! I checked my bags, and it worked! <3