The earliest recollection of this bug is traced back to PAN-OS 10.2.4 - March 25, 2026. This bug is fixed in PAN-OS versions 10.2.4. Fixed an issue where, after upgrading to PAN-OS 10.2.3, HA peers received conflicting ARP messages that indicated a duplicate IP address. For more information: https://docs.paloaltonetworks.com/pan-os/10-2/pan-os-release-notes/pan-os-10-2-4-known-and-addressed-issues/pan-os-10-2-4-addressed-issues