Thanks for taking the time to write in to us. I'm so sorry you ran into this issue. We are working on an update that will resolve this, but I don't have a definite timeline on when it will be released.
For now, there is a workaround, where in you uninstall the DLC via the Xbox, enter the game and open the DLC via the button at the bottom of the level select screen. This will prompt you to download the DLC and it should function properly. You may have to repeat this process on subsequent play sessions (we've gotten mixed reports from other users about this).
Thank you for your time and I apologize for the inconvenience!