Virtual Mailboxes are updated by the SQL job "Mailbox Maintenance - Populate Virtual Mailboxes" which runs every 60 minutes to give user access to messages in virtual mailboxes by adding message IDs in virtual folders to the appropriate mailboxes. No behavior has changed. This job calls dbo.AssignSecurityToMailBoxfor every existing virtual mailbox in the database.
If messages are not updating please make sure that the SQL Server Agent service is running.
To manually update virtual mailboxes right click Mailbox Maintenance - Populate Virtual Mailboxes- Archive Manager job in SQL Management Studio and choose Start Job at Step.