I just got a vanguard mentor missive from the bounty tracker, however, when I talk to the bounty tracker no exotic bounties show up for me to select. Some extra information is that I already have the exotic bounties for Bad Juju, Thorn and Invective and haven't handed them in or completed them yet. I also tried the bounty tracker in the reef, and logged out of Destiny and tried again, but still nothing has shown up.