The earliest recollection of this bug is traced back to PAN-OS 10.1.7 - July 29, 2024. This bug is fixed in PAN-OS versions 10.2.3, 10.1.7, 9.1.15. Fixed an issue where ARP broadcasts occurring in the same time interval and network segment as HA path monitoring pings triggered an ARP cache request, which prevented the firewall from sending ICMP echo requests to the monitored destination IP address and caused an HA path monitoring failover. Fixed an issue where ARP broadcasts occurring in the same time interval and network segment as high availability (HA) path monitoring pings triggered an ARP cache request, which prevented the firewall from sending ICMP echo requests to the monitored destination IP address and caused an HA path monitoring failover. For more information: https://docs.paloaltonetworks.com/pan-os/10-1/pan-os-release-notes/pan-os-10-1-7-known-and-addressed-issues/pan-os-10-1-7-addressed-issues https://docs.paloaltonetworks.com/pan-os/10-2/pan-os-release-notes/pan-os-10-2-3-known-and-addressed-issues/pan-os-10-2-3-addressed-issues https://docs.paloaltonetworks.com/pan-os/9-1/pan-os-release-notes/pan-os-9-1-addressed-issues/pan-os-9-1-15-addressed-issues