After about a year of beating the game, I decided to come back and try and 100% it. After I finished all of England then came to Vinland, this first mystery (breaking teeth not hearts) would not activate. There is no speech bubble in front of the guys head, but instead he just sits there with a blue dot above his head. I've attempted to reset/reload my game many times, but the quest is still broken. One thing I will mention is that he says every minute or so something about waves and dawn, and "I thought they would be here by now" or something like that. If anyone knows any solutions to this bug I would be eternally grateful. Thanks.