Copilot Narrative Visual in PowerBI

Hi Rohit_Singh_VC  ,
At this time, report authors don’t have any control to check how the backend Copilot model is updated or to change how the Narrative visual behaves internally. The formatting style like paragraph format or structured tables,bullets is fully controlled by the Microsoft‑hosted Copilot service.
Sometimes, when Microsoft updates the service or adjusts model routing, the format may temporarily change on its own. That’s why the behavior sometimes goes back to normal even when you didn’t change anything in the report or prompt.

You can try giving prompts that encourage structured output, but they cannot guarantee it every time. If this formatting issue starts happening again for many users, you can raise a support ticket with Microsoft Support so they can review this behavior from backend and assist you further.
If the issue continues, the support team will be able to investigate and guide you accordingly.
Please refer below link on how to raise a contact support or support ticket. 
How to create a Fabric and Power BI Support ticket - Power BI | Microsoft Learn

Regards,
Community Support Team.