Sharepoint Agent not talking in Teams chat

Hello,

I created an agent in one of our Sharepoint Site :

The agent works fine inside Sharepoint, but when I add it to a Teams group chat, whether the chat members all have access to the Sharepoint content and a Copilot licence or not, the agent doesn't "talk". It doen't even introduce itself :

I tried to follow many tutorials/documentation, such as https://support.microsoft.com/en-us/office/share-an-agent-from-sharepoint-in-teams-6dcbf7b5-8c13-44e5-a68a-dbd71fb76ad3, but found nothing on this issue.

Is there something I'm not doing right?

Thanks.

Regards,

J.L.