The earliest recollection of this bug is traced back to PAN-OS 10.1.0 - July 22, 2025. On the Panorama management server, local or Dedicated Log Collector mode cannot successfully join an ElasticSearch cluster when added to a Collector Group ( Panorama Collector Groups ) if the SSH key length for a Log Collector in the cluster is greater than 2048 characters. For more information: https://docs.paloaltonetworks.com/pan-os/10-1/pan-os-release-notes/pan-os-10-1-0-known-and-addressed-issues/pan-os-10-1-0-known-issues https://docs.paloaltonetworks.com/pan-os/8-1/pan-os-release-notes/pan-os-8-1-release-information/known-issues/known-issues-related-to-pan-os-8-1-releases https://docs.paloaltonetworks.com/pan-os/9-1/pan-os-release-notes/pan-os-9-1-release-information/known-issues/known-issues-related-to-pan-os-9-1-releases