pfSense New Version 2.5.2

I have a question about pfSense and hope that you could be of help. I have been running pfSense as a virtual server on Windows Server 2012 R2 for a few years without any issues.

I recently install the newest version 2.5.2-RELEASE. Since then the VHDx file is growing rapidly. I turned of logging under System Logs / Settings, but that does not help.

Does anyone have any suggestions how to fix this issue?