Hey @drheggman,
This sounds as though you've changed which EA Account was connected to your Xbox account.
Progress is currently stored on the EA Account itself so if you unlink an account that progress will be lost.
To correct this you would need to re-link the original account where all that content was earned. If you run into any trouble doing so please reach out to support and they'll be able to take a closer look at the account with you to get this cleared up.