Did achievement; not showing up or in my score

I skipped the Warden final boss fight to get the achievement Harbinger. My last teammate got downed, but I skipped the Warden. I made it through to the cutscene before the teammate died and the achievement is not on my Locked list, but it’s not in my Unlocked list or counted in my gamer score either.
The same thing is happening with the achievement Death From Above. I did it near the beginning like a YouTube guide said and it’s not on my locked list, but it’s not in my unlocked/gamer score either.
What do I do to fix this? Is this an issue I need to contact 343 directly for?