Bug Report: Teams Meeting Link Removed After Event Update

[TusharLokhande]

Describe the bug

When updating an existing Microsoft Teams meeting using the Microsoft Graph SDK (UpdateAsync on an event), even when setting IsOnlineMeeting = true and OnlineMeetingProvider = TeamsForBusiness, the event loses its Teams meeting link (OnlineMeeting.JoinUrl). The updated event is no longer treated as an online meeting.

Expected behavior

1. Create a Teams meeting using Microsoft Graph API with:

new Event {
    IsOnlineMeeting = true,
    OnlineMeetingProvider = OnlineMeetingProviderType.TeamsForBusiness
}

2. Successfully verify the meeting has a valid OnlineMeeting.JoinUrl.
3. Call UpdateAsync() on the same meeting with updated start/end times and again set:

newEvent.IsOnlineMeeting = true;
newEvent.OnlineMeetingProvider = OnlineMeetingProviderType.TeamsForBusiness;

4. Observe that after the update, the meeting no longer includes a Teams meeting link and is converted into a regular calendar event.

How to reproduce

Updating the event (with the same online meeting flags) should preserve the existing Teams meeting, including the join URL.

SDK Version

v5.x

Latest version known to work for scenario above?

No response

Known Workarounds

No response

Debug output

Click to expand log

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### Configuration

_No response_

### Other information

_No response_