Backwards Compatible Games not connecting.

Just make sure that your console is connected to Xbox Live when you are trying to install a backwards compatible game, even from disc, as all backwards compatible games need to be downloaded, not installed from disc.

Also it is up to the developers of games to decide if a particular title is made Backwards compatible or not, feel free to reach out to them and ask about making their game(s) backwards compatible too.

Here is a list of backward compatible games, its growing each day

https://www.xbox.com/en-US/xbox-one/backward-compatibility?xr=shellnav

And the download speed depens from your internet connection

Xbox does have backwards compatibility, but not all games are backwards compatible. That game is not compatible. https://www.xbox.com/games/backward-compatibility

While it is true that backwards compat is on hold. Every backwards compat licensing has to approved by the developer for that game to approve the ability of backwards compatibility. There are some developers unfortunately that will not allow there games
to be backwards compatible .

Also when you first put an Xbox 360 disc in an Xbox One that is on the backwards compatible list the console needs to be connected to the internet and online to allow it to download the backwards compatible version of the game to your console from Microsoft.