Completed “The Pillar of Autumn” and “Halo” in the Combat Evolved Heroic Playlist. Instead of getting their respective achievements for completion I ended up getting achievements for completing missions “Truth and Reconciliation” and “The Silent Cartographer”. This was on Steam.
I also completed the pillar of Autumn and received the achievements for truth and reconciliation along with the Halo 3 ODST achievement “Naughty Naught”: Kill 10 Engineers.
Same. It updated a few day later, though.