Increase log level for incoming notifications between Provisioning Server and Identity Manager.
If you ever had issues with inbound notifications and used this article preventative increase of log level may help troubleshoot this problem.
Identity Manager Standalone or Virtual Appliance.
In IMPM - System - Identity Manager Setup - see Log Level - set to Debug.
Then set im.provisioning.inbound (or im.provisioning) to DEBUG in IM (link)