The earliest recollection of this bug is traced back to PAN-OS 11.1.3 - March 18, 2025. This bug is fixed in PAN-OS versions 11.1.3. ( VM-Series firewalls in Amazon Web Services (AWS) only ) Fixed an issue where, when Gateway Load Balancer (GWLB) overlay routing was enabled, GWLB packets re-encapsulated with the incorrect flow cookie in the GENEVE header when transmitting the response back to GWLB. For more information: https://docs.paloaltonetworks.com/pan-os/11-1/pan-os-release-notes/pan-os-11-1-3-known-and-addressed-issues/pan-os-11-1-3-addressed-issues