EDIT: Found it in the known bug list. Guess I'll wait until HP fully replenishes.
The quest [Required]The Return of the Hero from the NPC Puka is not completable. Even though the NPC acknowledges that the quest is ready to be finished (with the closed book icon), he insists that the condition has not been met when talked to.
I tried forfeiting the quest and redoing it multiple times.
Images of problem