Totem of Nulgath [M] isn't working correctly. I left it on last night I got 100 essence of nulgath, however,it never went to the tainted elemental to get the lesser tainted core.
Use the Non-Member one, works just as well.
EDIT: Nevermind, the Death's Head is a MAJOR cock block. The bot almost only attacks him, plus if other people kill the Dark Makais, you don't get their drops. I would suggest killing the Tainted Elemental first, then starting the bot.