Halo: Nightfall without MCC (Not working)

I’ve bought Halo:Nightfall on my xbox (just the series, not the MCC), downloaded the Nightfall and the Halo Channel, but when I go in to the Halo Channel and try to play it still says “Buy Nightfall” rather than play. I know there’s been problems with Nightfall, but I can’t see any that relate to my situation. Anybody know what I might be doing wrong?

I already tried the troubleshooting from one of the other forums

Cheers!