If you get FTP connections errors similar to "Connection attempt failed with ECONNREFUSED - Connection refused by server" it is mostly because of the wrong FTP IP.

There is no FTP server installed on any of the SEO IPs of our service. The FTP servers are only installed on the WHM server.

To fix the problem, simply replace the IP of the FTP server with the IP of the WHM server of your domain and the connection should go through.