In the Stolen Lance timeline, there is a bug with the quest tracker.
After Argentus is killed and the player idles for some time, then approaches the middle of the arena again, the “God Hunter Argentus” quest will reactivate. This also messes up the Quest Journal, inserting the sub-point from the story quest “Finding Pannion”.
When leaving the echo, the game will correct itself by putting the timeline quest in the Completed section.