Create event sometimes returns 201 but no Teams meeting link

You’re seeing a successful event creation response, but the returned event occasionally lacks onlineMeeting.joinUrl even though isOnlineMeeting and the Teams provider were supplied. A 201 confirms that the calendar event was created; it does not independently prove that online-meeting properties were populated. Supply and retain a unique transactionId on the original POST, store the returned event ID, and issue a GET selecting isOnlineMeeting, onlineMeetingProvider, and onlineMeeting. Do not create a second event as the first recovery step, because retries without transactionId can produce duplicates. Log the sanitized request and response plus client-request-id, response request-id, and Date. Also verify that the organizer calendar lists teamsForBusiness in allowedOnlineMeetingProviders. If the follow-up GET still returns no joinUrl, open a Microsoft support case with those correlation values and UTC timestamps. I cannot find an official documented intermittent defect matching this exact behavior