The earliest recollection of this bug is traced back to PAN-OS 12.1.3 - March 16, 2026. This bug is fixed in PAN-OS versions 12.1.3. Fixed an issue where the ADEM plugin was not compatible with PAN-OS 12.1.2, which prevented installation of the plugin and disabled the ability to monitor remote sites on firewalls using the ADEM functionality. To use this fix, you need the following compatible versions: ADEM 1.1.0-h3 and SD-WAN plugin 3.4.0. For more information: https://docs.paloaltonetworks.com/ngfw/release-notes/12-1/pan-os-12-1-3-known-and-addressed-issues/pan-os-12-1-3-addressed-issues