I cannot add backup node, task "Install additional packages on node 'backup.example.com' according role PPA_BACKUP" fails with on of the errors below:
"Transport error: unable to list directory: Curl error: FTP: login denied". Unable to execute the command '/usr/local/psa/bin/server_pref'. Unable to make test connection with to specified. Please check login, password and FTP mode (-use-ftp-passive-mode option). Details: Server name is invalid. You can use alphanumeric, dash and underscore symbols in the username.
The issue is caused by special symbols that were used in password. It is not possible to register node with "Backup Server" role if FTP password contains special symbols ($,#, @, !, ?, etc.).
Redeploy node using a password without special symbols.