Xbox One disc problem?? Help?

I got this Xbox One recently and GTA V along with it, and so far that's been the only disc to go in the console.

Now I'm trying to play Fable 2 for Xbox 360 (which is one of the backwards compatible games), except when the disc goes in it still shows me the option for GTA on the menu. The console doesn't even acknowledge that a new game's been inserted.

There aren't any "error"s coming up or anything, Fable just isn't showing. When I click on the GTA box it just says "if you have a game disc, insert it now", so it knows the GTA disc isn't in there.

I've never owned an Xbox before so I don't know if I'm missing something obvious? Please help! Thank you:)