Do you Excluded registered devices into You Device Rule which block all external USB devices?
I have created a definition to exclude blocking of certain USB devices with their VID and PID.
Thanks for your response.
Did this rule work correctly?
Goto DLP incident manager and open the specific event and check which rule is blocking the device.
On the same page, click on actions and click "export device parameters".
Open the DLP policy console page, goto device definiton and import the exported device parameter. If it is a PnP rule, import it as a plung and play device definition.
Exclude the specific device definition in that rule, it should work.
Generally, you will get two different events when you insert dongles on the client machine. So, export both the parameters and import it in DLP policy page.