There are several possible reasons why events are not showing up when you search for a specific attendee in Microsoft Calendar:

1. Check to make sure the attendee is included in the ‘Attendees’ field when scheduling the event in Microsoft Calendar.
2. Verify that the attendee is invited using a valid email address in Microsoft Calendar.
3. Ensure that the attendee is located on the same Microsoft Calendar server.
4. Confirm that the event is visible in the attendee’s calendar list in the main Outlook view.