The earliest recollection of this bug is traced back to PAN-OS 9.1.10 - July 29, 2024. This bug is fixed in PAN-OS versions 9.1.10. Fixed an issue with the Panorama web interface where, when all device groups and templates were selected, a load configuration operation failed. This was caused by the XML cache rebuilding for each device group and template iteration. For more information: https://docs.paloaltonetworks.com/pan-os/9-1/pan-os-release-notes/pan-os-9-1-addressed-issues/pan-os-9-1-10-addressed-issues