The earliest recollection of this bug is traced back to PAN-OS 8.1.17 - January 09, 2024. This bug is fixed in PAN-OS versions 9.1.5, 8.1.17. Fixed an issue where the firewall dropped GTP packets with Delete Bearer messages for EBI 6 if they were received within two seconds of receiving the Delete Bearer messages for EBI 5. For more information: https://docs.paloaltonetworks.com/pan-os/8-1/pan-os-release-notes/pan-os-8-1-addressed-issues/pan-os-8-1-17-addressed-issues https://docs.paloaltonetworks.com/pan-os/9-1/pan-os-release-notes/pan-os-9-1-addressed-issues/pan-os-9-1-5-addressed-issues