I discovered this bug when I wanted to suppress automatic discovery of interfaces via SNMP. The intention was to let discover only interfaces which I explicitly defined in the Provisioning Group. In order to achieve this, I defined the following Foreign Source Policy:
class=Match IP Interface
When a Provisioning Group with such Policy is imported, all defined services are discovered and immediately after that deleted (see attached screenshot of the event log). The same behavior can be observed when Rescan of the node is performed. First Rescan discovers all services, second Rescan deletes them.