Exchange Online - Unable to change end time of eve

问题:

Assume the following:

1. In Office365 a room resource has been created with the default settings.
2. A meeting is booked at this room.
3. The meeting has started.

The organizer then changes the end-time of the meeting (either to extend it or end it early).

The room auto-replies with Your meeting request was declined. The invitation was declined because it occurred in the past.

Interestingly, at this point, the event then completely disappears from the room's calendar - as if it never existed.

This is a reasonable use-case. Which settings would allow the organizer to achieve the above scenario without being declined?