Prep data for AI - AI instructions ignored by Copilot, no Copilot indexing option in the settings

[TomaszKoc]

Copilot ignores AI instructions added in Prep data for AI interface. Q&A are turned on, dignostic logs show that custom instructions are there but "IndexingEnabled": false  and there is not option in Prep data for AI settings to turn it on (option not visible in the interface, both in service and Desktop). What is suprising, in rare cases it looks like Copilot followed the custom instruction e.g. in some but not all summaries generated with subscriptions - no true patern detected there.
Issue appears in import / direct query/ live connection modes, Desktop is up to date (April 2026 edition), aplies to evey semantic model tested.
"CopilotAgentId": "PuPr_Service_ReportConsumptionAgent_202408" in the service.
Any thoughts or suggestions how to make it work?

[Natarajan_M]

hi @TomaszKoc , Please check if you are using the latest version of the pbi desktop 

[TomaszKoc]

Microsoft refers to a different setting which is not visible (the one from the documentation, screen shot below, I don't see that in the app).
I've tested the DAX one, you mentioned - no effect.

[v-hjannapu]

Hello @TomaszKoc,

The option mentioned in Microsoft documentation is not available in all tenants yet. It depends on backend enablement and feature rollout, so not seeing that setting in Desktop or Service is expected in some cases.

Since this is happening across different models, it looks more like an environment or feature availability issue rather than anything specific to your setup.

You can just check once with your admin if Copilot is fully enabled at tenant level, as this setting is controlled from there.

If you still encounter any issues, feel free to reach out here. I'm happy to assist you
Regards,
Community support Team.

[v-hjannapu]

Hi @TomaszKoc,
I hope the above details help you fix the issue. If you still have any questions or need more help, feel free to reach out. We are always here to support you.


Regards,
Community Support Team.

[TomaszKoc]

Thank you for the reply. Issue persists, I've raised a ticket with Microsoft support, but there seem to be no obvious solution, looks like a bug in the service or incomplete roll out. Copilot is enabled and it seems that it sometimes follows the instructions (e.g. with Copilot summary for subscriptions), but for most of the time it doesn't. Still no option to enable indexing, but the previous option with DAX queries for Copilot disappeared (after I raised the ticket). No I idead how to turn on indexing (IndexingEnabled": false).

[v-hjannapu · Accepted solution]

Hi @TomaszKoc  ,
This looks like a rollout gap. The Indexingoption isn’t available in all tenants yet, so seeing"IndexingEnabled": false is expected. Until indexing is enabled, Copilot may apply instructions inconsistently.

Since the old DAX option was retired, the new indexing pipeline is required. Best step is to confirm with Microsoft support if your tenant is included in the rollout. Once indexing is enabled, the toggle will appear and instructions should work reliably.

Please find the attached file for your reference:
Prepare Your Data for AI (preview) - Power BI | Microsoft Learn

Regards,
Community Support Team.

[v-hjannapu]

Hi @TomaszKoc,
I hope the information provided above assists you in resolving the issue. If you have any additional questions or concerns, please do not hesitate to contact us. We are here to support you and will be happy to help with any further assistance you may need.

Regards,
Community Support Team.

[Natarajan_M]

Hi @TomaszKoc , Did you get a chance to turn on the toggle in the AI prep ?

https://learn.microsoft.com/en-us/power-bi/create-reports/copilot-prepare-data-ai-settings