So I have seen a lot of threads on this but no responses to the op. I have finally been going through and playing the campaigns. I beat Halo: CE and Halo 2 and noticed that when I finished H2 I had the nameplate for beating the campaign on legendary for CE but not H2. I thought maybe it would take a bit of time to unlock so I just ignored it. I just finished H3 and went to check and the H3 nameplate unlocked immediately upon completion. I went back to missions on H2 and it shows all are completed on legendary. Was wondering if anyone has a solution to this problem that excludes having to play through H2 again? Any help is appreciated.