Hi @clementt it is no problem! I apologize for the delay on response, if we set the SSO Cookie Timeout to something like 1 minute. And we proceed with our application, we perform the authentication flow and establish a session, we perform a checkSession call the call will work. If we wait for the session to expire, for example around 2 minutes after (remember we set SSO Cookie timeout to 1 minute and we perform a checkSession call it will fail. But, if we set to call checkSession before the SSO Cookie Timeout then we can silently re-authenticate the user and they can continue to use the application.