React: Google "One Tap" callback function not being called

<script src="https://accounts.google.com/gsi/client"></script>
...
declare var google: any;
...

  useEffect(() => {
    const handleCredentialResponse = (response: any) => {
      console.log(response);
    };
    const client_id = process.env.REACT_APP_GOOGLE_CLIENT_ID;
    const callback = handleCredentialResponse;
    const auto_select = true;
    google.accounts.id.initialize({ client_id, callback, auto_select });
    google.accounts.id.prompt((notification: any) => {
      console.log(notification);
    });
  }, []);

Why does handleCredentialResponse not get called at all? The user is prompted to log in, they hit continue and then the function never gets called! Grrr! Above taken from docs here and also here

The notification logs out

nl {g: "display", h: true}
nl {g: "skipped", l: "issuing_failed"}