The earliest recollection of this bug is traced back to PAN-OS 10.1.0 - May 06, 2026. This bug is fixed in PAN-OS versions 10.1.2. Changing the port speed on a PA-400 Series firewall from auto-negotiate to 1G may cause the dataplane port to flap intermittently and result in a loss of traffic. ( PA-400 Series firewalls only ) Fixed an intermittent issue where changing the port speed from auto-negotiate to 1G caused the dataplane port to flap, which resulted in lost traffic. For more information: https://docs.paloaltonetworks.com/pan-os/10-1/pan-os-release-notes/pan-os-10-1-0-known-and-addressed-issues/pan-os-10-1-0-known-issues https://docs.paloaltonetworks.com/pan-os/10-1/pan-os-release-notes/pan-os-10-1-1-known-and-addressed-issues/pan-os-10-1-1-known-issues https://docs.paloaltonetworks.com/pan-os/10-1/pan-os-release-notes/pan-os-10-1-2-known-and-addressed-issues/pan-os-10-1-2-addressed-issues