Notification emails stating "[Person A] has joined the meeting..." not working consistently

[amytutoring]

Most of the time I receive an emailed notification that says " 'Name' has joined your Personal Meeting Room" if I have not started the meeting. However, sometimes I don't get any notification and I have no idea that someone is waiting for me. I can't figure out why and it's so frustrating. The feature is useless if I can't rely on it.