As an update to my above message.
When you inserted the disc into your Xbox One for the first time, you will have been prompted to install/download an update for the game, which will have been approximately 22GB. Did you accept the update or did you choose to 'Update Later'?
If you chose 'Update Later', one suggested workaround is to uninstall all HITMAN content, insert the disc again (as if it was the first time) and then accept this prompted update.
Please feedback here with any success or issues with the above suggestion. Thank you again for your patience.