Quest bugged?

Hi!
I've been trying to complete "You reap what you sow" quest in Zul'drak. When i click the quest item while targeting Quetz'lun, the pilar appear but not the animation and the prophet doesn't react and it doesnt become a troll i can kill.

I try /reload walking away and back while passing trough the gate and staying alive and having the mob turning yellow. But still nothing happen when i click the item aside from the pillar appearing.

Any idea?

Anyone as a solution?

Tried again this morning. This time i walked on foot from the archway up to the prophet and this time it worked..