Copilot Studio Agent via ACS receives WhatsApp messages but does not send outbound replies.

(1) Share

Report

Posted on by VR-30120950-0

Hi all,

I'm facing an issue while setting up the WhatsApp channel in Copilot Studio using Azure Communication Services (ACS).

Problem
The WhatsApp channel connects successfully and messages reach ACS, but the Copilot agent never receives them.

After investigating, I found that:

The Event Grid System Topic is created
However, the Event Subscription is NOT created
As a result, events are not forwarded to the Copilot agent

Expected flow
WhatsApp → ACS → Event Grid (System Topic + Event Subscription) → Copilot Studio

Current state
WhatsApp → ACS → Event Grid (System Topic) → (stops here)

What I've already validated

I have Owner permissions at subscription level
Microsoft.EventGrid provider is registered
I have reconnected and republished the channel multiple times (waiting between attempts)
No errors are shown during publishing
ACS is correctly receiving messages

Blocking issue

The Event Subscription is never provisioned
Copilot Studio does not expose any webhook URL
Because of that, I also cannot create the subscription manually

Regarding suggested workaround (Event Grid Viewer)
I tested the approach of deploying the sample Event Grid viewer:
https://github.com/Azure-Samples/azure-event-grid-viewer

While this provides a valid webhook endpoint, it does not solve the issue because:

Copilot Studio still does not generate or expose its own webhook
The integration requires the Copilot-managed endpoint, not a generic one
The core problem is that the Event Subscription is not being created by Copilot Studio, not the absence of a generic webhook

This confirms the issue is not with ACS or Event Grid itself, but with the Copilot Studio provisioning step

Question
Has anyone encountered this issue where:

System Topic is created
Event Subscription is missing
No webhook is generated by Copilot Studio?

Is there any way to:

Force the provisioning?
Retrieve the webhook URL used internally by Copilot Studio?
Or confirm if this is a known issue requiring escalation?

This is currently blocking the integration, so any guidance would be really helpful.

Thanks in advance.

Categories:

Publish & channel management

I have the same question (0)

All responses (2)

Answers (0)

Sort by

Suggested answer

Valantis 6,233 on at

Like (1)

Report
Copy link

Link copied!

Hi @VR-30120950-0,

This is a confirmed known issue reported by multiple users. The Event Subscription not being created automatically by Copilot Studio during channel setup happens when the provisioning step fails silently.

The confirmed fix from Microsoft Q&A:

1. Go to Copilot Studio > Channels > WhatsApp
2. Disconnect/remove the current WhatsApp configuration completely
3. Wait a few minutes
4. Re-add the channel: select your Azure subscription, ACS resource, and phone number again
5. Click Deploy

This re-triggers the provisioning step which should automatically create the Event Grid subscription and Copilot Studio's internal webhook endpoint. You cannot create the subscription manually because the webhook URL is managed internally by Copilot Studio and not exposed.

If the Event Subscription still doesn't appear after reconnecting:
- Check that the system-assigned managed identity is enabled on your ACS resource
- Verify the Bot Channel Events identity has EventGrid event subscription permissions on the resource group
- Check Azure Monitor > Event Grid diagnostics for any auth failures during provisioning

If reconnecting multiple times doesn't work, raise a Microsoft support ticket. This is a backend provisioning issue that support can trigger manually on their side.

Best regards,

Valantis

✅ If this helped solve your issue, please Accept as Solution so others can find it quickly.

❤️ If it didn’t fully solve it but was still useful, please click “Yes” on “Was this reply helpful?” or leave a Like :).

🏷️ For follow-ups @Valantis.

📝 https://valantisond365.com/

💼 LinkedIn

▶️ YouTube

Was this reply helpful? Yes No
Suggested answer

11manish 2,782 on at

Like (0)

Report
Copy link

Link copied!
Given that:

ACS receives messages successfully.

The Event Grid System Topic is created.

The Event Subscription is never created.

No Copilot webhook endpoint is exposed.

Re-publishing and reconnecting do not resolve the issue.

This strongly suggests a Copilot Studio provisioning failure rather than a configuration issue within ACS or Event Grid.

At this stage, I would recommend opening a Microsoft Support ticket

Since the endpoint is Microsoft-managed and the Event Subscription is expected to be created automatically, Microsoft Support has access to backend provisioning

logs that are not visible to customers and can determine whether this is a known issue, a provisioning defect, or a tenant-specific configuration problem.

Was this reply helpful? Yes No