I tried to finish quest Master or Elixirs and I was unable to find Recipe: Elixir of Major Defense. All wikis say it should be sold by Haalrun in Zangarmarsh but he simply doesnt offer it. Its not showing as bought out waiting to restock, he just simply doesnt have it. According to wiki he is the only source of that recipe.
"Its not showing as bought out waiting to restock" well if item bought out and its on cd, merchant will not show you anything, so i think you just need to catch it in right time
You most probably got unlucky. Yesterday I camped him and collected herbs around and finally got all 3 recipes from him. It worka, just some patience is requiem.