I’ve had this account since 2011 and have played every Halo game. Why does my service record not show any data for these 2 games? It says I haven’t played them at all. My rank for Halo: Reach is also inaccurate.
It will be due to your gamertag change, older games aren’t able to automatically sync things up. If you still have access to the games, you can go back and play something for a little bit - campaign, multiplayer, forge, customs. As long as you’re connected to Xbox Live, everything should sync up again shortly after that