The earliest recollection of this bug is traced back to PAN-OS 8.1.20 - January 09, 2024. This bug is fixed in PAN-OS versions 8.1.20. Fixed an issue in Panorama where the show config diff command was not working correctly and produced unexpected output. For more information: https://docs.paloaltonetworks.com/pan-os/8-1/pan-os-release-notes/pan-os-8-1-addressed-issues/pan-os-8-1-20-addressed-issues