Missing "outside" armors

Hi,

So I have watched all of Halo Nightfall (got all the second stories on all of the videos and it says 2/2 rewards); I have completed the “Your journey begins” and “Cairo station” (working on finishing the campaigns on Legendary). However I do not have the Nightfall, , mark VI or Mark VI Scarred armors.I have tried turning the Xbox on and off, signing on and off, and cant seem to get them.

How do I get them? What am I doing wrong?

Thanks