I joined in on a buddy when we were both on the last step for Salvation's Grip, where you steal it and then complete the scenario with it. I joined on him after the part where you take the weapon. When I completed the mission, my quest was updated and it told me to speak to The Drifter in the annex. The Drifter updated the quest and completed the quest chain, but I did not have the weapon in my inventory. Instead I only have a bugged STASIS CONTAINMENT DEVICE with a red objective box and no description in my inventory. It cannot be dismantled and there is no longer an exotic quest in my Quests tab. I am stuck and I cannot continue this part of the story without Salvations Grip.