In a Microsoft Exchange Server 2016 environment, consider the following scenario:
You have a mailbox that has mailbox audit logging enabled.
You do a grouped operation (for example, that you delete multiple messages at one time would be audited).
You run the Search-MailboxAuditLog –ShowDetails cmdlet on the mailbox.
In this situation, you may not see all the messages that are included within the grouped operation in mailbox audit logs.
This issue occurs because the indexing of audit entry isn't correctly handled.
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.
Learn about the terminology that Microsoft uses to describe software updates.