Hi Richard,
I know that you want to view detailed reports of the DLP hits. I suggest you download Mail Protection Reports for Office 365 to view the details.
Moreover, if a DLP is set to test without policy tips, it means all the emails will be evaluated but the mail flow won’t be affected. If an email hit the DLP, the policy tip won’t be shown to the sender in Outlook. And it will still be recorded in the report.
For detailed information, please see View and download reports about service usage in Office 365.
Best Regards,
Bruce Zhou