Greetings Exile,
The future patch we’re preparing will assist with overall performance, missing assets, and many other bugs and issues specific to consoles. However, with the information available from your case we cannot say for sure it will fix your saved file.
In the meantime, we suggest you try to perform a soft factory reset while keeping games and apps.
Please ensure that your save is stored on the XBOX cloud before moving forward.
We hope this helps.