In a highly available Portal deployment, the primary node reverts to the 'Create New Site' state, if the primary node loses connection to the content directory.
1) On primary node, confirm that [Portal content path]\arcgisportal\db\.config-store-connection.json matches [Portal install path]\portal\framework\etc\config-store-connection.json.2) On standby node, backup both of those files, then overwrite them with the two files from primary.3) Update the shared content directory’s nodes.properties to include the standby.4) Start the Portal for ArcGIS service on the standby node.