Can't see which missions I didn't finish.

Games Other Halo
1

I’m playing solo legendary for the Mark VI armor but yesterday after I finished a mission it didn’t register, it said I completed 1 mission after completing 3. Now today it says I completed 5 missions and I did. Did it fix? Do I not have to go back and play them now for the Mark VI? and if I do how do I see which mission I need to complete again?

2

Anyone?

3

I just finished a mission and the commendation thing when you complete a mission said 3/8 but when I go to my service record it says I completed 6 missions, will I get the helmet?