I have enabled dictation in the preferences, but it fails to start.

When I tap fn fn, the Icon with three dots appears, and quickly disappears. I don't see a microphone.

My system is connected to the Internet with an ADSL router, through an Ethernet LAN. I have temporarily disabled the router firewall, but it does not seem to help.

My system is in French (but I think "Dictation" should work since it is indeed called '"Dictée")

How can I have logs?

What can I investigate?