The earliest recollection of this bug is traced back to PAN-OS 9.1.6 - July 29, 2024. This bug is fixed in PAN-OS versions 9.1.6. Fixed an issue where a process ( httpd ) restarted during Security Assertion Markup Language (SAML) logout sessions initiated from the IdP. For more information: https://docs.paloaltonetworks.com/pan-os/9-1/pan-os-release-notes/pan-os-9-1-addressed-issues/pan-os-9-1-6-addressed-issues