Don't expect WHMCS backups to work if you secure your servers.
All my servers are set to use SFTP only and using a custom port.
so in WHMCS under the Database Backups i have Daily Remote FTP Backup set up and i know all the settings are correct, but the cron always states
Cron Job: ERROR : FTP Backup - Could not connect to backup.hostname
so contacted WHMCS support who told me to make sure my servers have the port open which they have and the IPs whitelisted.
(how i like how they reply to you as if you were a child and not know such things)
anyway after checking and telling them they are all set and open and whitlisted i get this
Port ***** seems to be SFTP and not regular FTP. I believe this is why it is not working, as SFTP is not supported at this time.
so they don't support secure servers and yet they are always going on about making your WHMCS installation secure