Halo 3 Cortana bug

Completed the level Cortana on Lendagary but it doesn’t show it as completed on review. Is there anyway to fix this bug?

I have the same issue. I completed the whole level in legendary in solo, in coop, with and without skulls on…
I found, for now, no way to fix it.

I have gone over the scenarios using acrophobia skull and I think I found a way to fix it…
you have to complete the level in every difficulty, starting in easy, then normal… I don’t why there is this strang bug but it seems than doing it can fix this bug.