The earliest recollection of this bug is traced back to PAN-OS 8.1.15 - January 09, 2024. This bug is fixed in PAN-OS versions 9.1.2, 8.1.15. Fixed an issue on an M-Series appliances in an HA active/passive configuration where the schedules ( Device > Dynamic Updates ) were unresponsive after a failover or restart of Panorama. Fixed an issue on an M-Series appliances in a high availability (HA) active/passive configuration where the schedules ( Device > Dynamic Updates ) were unresponsive after a failover or restart of Panorama. For more information: https://docs.paloaltonetworks.com/pan-os/8-1/pan-os-release-notes/pan-os-8-1-addressed-issues/pan-os-8-1-15-addressed-issues https://docs.paloaltonetworks.com/pan-os/9-1/pan-os-release-notes/pan-os-9-1-addressed-issues/pan-os-9-1-2-addressed-issues