### Answer
It seems like you might be encountering an issue related to the assistant's configuration or an error in the system. To troubleshoot this situation:
1. Check the Assistant Configuration: Ensure the assistant's LLM and transcriber settings are correctly configured in your dashboard. Make sure that the language settings for both the LLM and the transcriber are properly set to handle French.
2. Review Logs for Errors: Check the call logs in your dashboard for any error messages or alerts that could indicate what went wrong during the call. Look for errors related to speech recognition or LLM processing.
3. Test with a Different Configuration: Temporarily change the LLM or transcriber configuration to see if the issue persists. This can help isolate whether the problem is with a specific component.
If these steps do not resolve the issue, it could be related to deeper system errors or misconfigurations not directly accessible or rectifiable from the user dashboard. In such cases, contacting Vapi support with the call ID and details of the configuration might be necessary to resolve the issue more effectively.