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, 9.1.11. Fixed an issue where packets were dropped unexpectedly due to errors parsing the IP version field. 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-9-1-11-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