Assassin's Creed Valhalla

So I had a bug pop up and now I can't finish a mission. I came across Halfdan sitting on a bench and he told me about throwing his hammer out into the forest. Nothing came of it so I moved on. Later on I came across his healer who tells me to go find Halfdan because he lost his hammer. Now Halfdan won't talk to me anymore and the quest won't go forward.

While this has been a pretty buggy game, I've still enjoyed it. I just hope they can patch this so I can finish it. It's one of the last quests I have left.