Achievements not working in Reach Matchmaking

So I have several times done certain things like destroyed ghosts with armor lock and killed people in Rocket Race but the achievements are still locked. Any idea why? Those are not the only two online achievements I should have unlocked.

Have you bought the maps?

Not the new ones but these shouldn’t require them. They existed before the maps did.

> Not the new ones but these shouldn’t require them. They existed before the maps did.

no they didn’t

Goobot is correct as far as I know.

> > Not the new ones but these shouldn’t require them. They existed before the maps did.
>
> no they didn’t

He is right. You need to buy the new maps for the new achievements.