The earliest recollection of this bug is traced back to PAN-OS 9.1.1 - July 22, 2025. This bug is fixed in PAN-OS versions 9.1.1. Fixed an issue on Panorama where when viewing Unused Rule Usage in Policy Optimizer, devices without a hit count had the incorrect date and time instead of displaying no values. Now, if the rule has not been used, the dates and times are displayed with a hyphen (-). For more information: https://docs.paloaltonetworks.com/pan-os/9-1/pan-os-release-notes/pan-os-9-1-addressed-issues/pan-os-9-1-1-addressed-issues