1. Check your Microsoft calendar settings in the calendar app to ensure events are shared with other people and appear on your calendar.

2. Check whether the event is noted in the Outlook calendar.

3. Make sure you are subscribed to the correct Microsoft calendars.

4. Check to see if you have accepted the invitation or if its still pending in your Microsoft Outlook calendar.

5. If you are using a shared calendar, double-check the settings to make sure events appear in the shared view.