@Caulderone Lorenzo and Willy are Natural Origin contacts as well. One gets introduced to only one of the three at random when one reaches level 9. So no, I don't have one of them as a contact and didn't complete the arc through them. I think the only way to get to the Bonfire arc is through Ouroboros for me.
@srmalloy Good to know that I'm not the only one. I checked the forums but couldn't find anything about this bug.