Reports summarized by policy and policy rules will show incorrect match counts within the Incident Report.
The actual incident snapshot will have correct match counts pertaining to the number of rules violated per policy.
Row and Column counts are adversely affected by compound rules and report summarization.
Because the incident and match counts are correct, per incident, no further action is required.
Workaround for statistical reporting for DLP administrators. Remove the secondary summarization from the policy summary settings.