Why is my mission no longer showing up in the app?
When a mission is no longer available or showing in the Invites tab, it means you've already accepted and declined that invitation. All accepted missions will be available to you in the In Progress tab.
When a mission is no longer available or showing in the In Progress tab of the app, it means that your mission leader has closed you out in the mission. Chances are they are reviewing your entries and will be reaching out with more information, including your reward information, in the next couple of days.