It looks like if there are some problems with conversation requests.
A student requested a conversation with me. I answered and suggested another time. The student got no notification about my answer (no email).
Than the student changed again the time and wrote a note. I got no email too. I think something is going wrong there. It is important to send an email to let the student and the tutor know if something has changed.
Another problem: Last week something strange happened. The student suggested a conversation on Wednesday. I answered and suggested another time at the same day. This suggestion appeared on Thursday (maybe because of the time difference?). I neglected the conversation on Thursday and my student changed the conversation time on Wednesday. Now there was a difference between the notification on the Speaking page and the notification on the Welcome page.