Room mailbox accepts a meeting as “Free” if a booking delegate is set in Exchange Server 2019 and 2016

Symptoms

In a Microsoft Exchange Server 2019 or Exchange Server 2016 environment, consider the following scenario:

• You create a room mailbox and assign a booking delegate that accepts or declines booking requests by using the cmdlet that resembles the following:

Set-CalendarProcessing -Identity “Room 221” -AllRequestInPolicy:$true -ResourceDelegates “UserA@contoso.com” -AllBookInPolicy:$false -AutomateProcessing 'AutoAccept'

• UserB creates a new meeting by setting the Show As field as Free. In addition, UserB adds UserC and Room 221 as attendees.

• UserA accepts the meeting request.

In this situation, you find the room still shows as free, which is not expected. It should be shown as busy after it accepts the meeting request.

Resolution

To fix this issue, install one of the following updates:

• The Cumulative Update 3 for Exchange Server 2019 or a later cumulative update for Exchange Server 2019.
  

• The Cumulative Update 14 for Exchange Server 2016 or a later cumulative update for Exchange Server 2016.

References

Learn about the  terminology that Microsoft uses to describe software updates.