Finished lightfall legendary campaign today with a friend of mine, both of us didn't get an exotic. All of the missions don't have "yet to complete this challenge", got the triumph for completing legendary campaign, did all of it on one character, no exotic reward at the end. After some investigation noticed that triumphs under the one that is given for completing the legendary campaign are also uncompleted (these triumphs are “complete first contact on any difficulty” and others containing part of the missions) although it is impossible to complete the legendary campaign without completing the individual missions from the campaign. Tried running first contact on classic mode but that didn't register either. There is probably some kind of bug, would like to see it fixed soon