The earliest recollection of this bug is traced back to PAN-OS 11.1.4 - December 03, 2025. This bug is fixed in PAN-OS versions 11.1.5. In the event of a cluster manager restart on the leader node of an NGFW cluster, traffic stops because the state machine transitions to unknown and the leader is not changing. Fixed an issue where, after a cluster manager restart on the leader node of an NGFW cluster, traffic stopped due to only the state machine transitioning to unknown and not the leader. For more information: https://docs.paloaltonetworks.com/pan-os/11-1/pan-os-release-notes/pan-os-11-1-4-known-and-addressed-issues/pan-os-11-1-4-known-issues https://docs.paloaltonetworks.com/pan-os/11-1/pan-os-release-notes/pan-os-11-1-5-known-and-addressed-issues/pan-os-11-1-5-addressed-issues