I have had a similar issue where he would refuse to even acknowledge that I was on the quest. It was definitely the right NPC, but no matter what I did I couldn't make the NPC that was in my party appear in the target village, nor could I get the target NPC to deliver the quest dialogue and allow me to proceed. I also still had the quest NPC in my party after the quest failed due to timeout, and he behaved as a companion (and I later found him in a tavern).