Navigate to Analytics > Policy to see information related to the network policy.

The panels at the top of this dashboard show the rule hits logged in the selected reporting period by severity. The charts show which policy rules were hit. The Policy Actions chart shows the number of times Threat Defender performed the drop traffic action (blocked) and the reject traffic action (teardown) of a policy on the network traffic. The relationships of logged severities and assets are also displayed.

From here, you can further investigate the network traffic.