The treasure chest across the bridge from Bruhamarr Outpost requires 2 keys to unlock. One is carried by an enemy on the Bruhamarr side of the bridge. I killed the enemy, but during the killing animation, I was killed as well. However, since I had not yet died in Vinland, instead of reverting back to an old save, it instead revived me and told me about Elderberries. Going back to the area, the key is not on the corpse any longer, or is it in my inventory that I can tell. It seems that by triggering the revival, it messed up the transfer of the key.
Assuming this is necessary for the "do everything in the game" achievement, I would like to be able to loot this treasure. I was hoping going back to England and then returning to Vinland later would respawn some of the enemies such as this, but it seems this is not the case. Would be happy to help troubleshoot.
I am running an Xbox Series X digitally downloaded version of the game.