The Host IPS ePO Property Translator server task runs every 15 minutes by default to convert system client properties into adaptive client rules that are displayed in the client rules tabs of the Host IPS Event Reporting display. Excessive processing of client rules can cause increased CPU consumption for ePO-related processes. Additionally, malformed properties collected from the end system might cause Property Translator errors. The task is set by default to disabled. If you wish to automate it over and above the default 15 minute execution, you can. As you discovered, this task runs automatically every 15 minutes.