Mission completion glitch

Xbox 1S, Mission: Beyond the barricade.
Was in multiplayer mode and someone joined and ran into the gas filled house and took the letter while I was outside killing runners.
I have both clues and everything in the village is dead. I am not done as it says I am missing a clue, but both the letter, and message are in my log. I have tried dying and respawning and running back, logging out and back in. This has gone on for 3 days already. Not sure how to complete the mission when I am already in possession of both clues and the is what it is requiring me to get.