I'm playing Iron Banner games. I decide to do medals while playing Iron banner. I attempt Mission Control. I complete a Mission Control medal, and see the medal in game appear in front of my face. I don't earn the Mission Control in my triumphs. I am sad. Why did I not earn the triumph?
Iron Banner has its own set of medals separate from Crucible, only Crucible medals count for specific Triumphs/Seals/Titles.