This is the second time I am coming to these forums, I have seen lot's of people having the same issue as me, we have completed the campaign on our character, every single one is complete, in my case I only have one character, and Nimbus is flashing on the map telling me to get it, but it just shows bounties. Everywhere on the internet says that maybe a mission is missing on legendary, or that you didn't complete it all on one character. Some say to go on a wild goosechase talking o people who arent even on Neomuna anymore (osiris/caital).