Unable to add SFTP destination to backup Cyberpanel

Have been struggling to get sftp connected to backup our Cyberpanel server, but keep getting errors:

Host XXX.XXX.XXX.XXX not found in /root/.ssh/known_hosts
Timeout exceeded.

command: /usr/bin/ssh
args: ['/usr/bin/ssh', '-o', 'StrictHostKeyChecking=no', '-p', '666', 'cyberpanel@XXX.XXX.XXX.XXX', 'mkdir ~/.ssh || rm -f ~/.ssh/temp && rm -f ~/.ssh/authorized_temp && cp ~/.ssh/authorized_keys ~/.ssh/temp || chmod 700 ~/.ssh || chmod g-w ~']
buffer (last 100 chars): b''
before (last 100 chars): ''
after:
match: None
match_index: None
exitstatus: None
flag_eof: False
pid: 125621
child_fd: 5
closed: False
timeout: 3
delimiter:
logfile: None
logfile_read: None
logfile_send: None
maxread: 2000
ignorecase: False
searchwindowsize: None
delaybeforesend: 0.05
delayafterclose: 0.1
delayafterterminate: 0.1
searcher: searcher_re:

Am able to connect to server via Filezilla locally and remotely, but from Cyberpanel get error.

Filezilla server log (when connection from Cyberpanel attempted):

<Date> Info [Type] Message
<21/07/2022 3:59:38 PM> FTP Session 27 XXX.XXX.XXX.XXX[Response] 220-FileZilla Server 1.5.0
<21/07/2022 3:59:38 PM> FTP Session 27 XXX.XXX.XXX.XXX[Response] 220 Please visit https://filezilla-project.org/
<21/07/2022 3:59:38 PM> FTP Session 27 XXX.XXX.XXX.XXX[Command] SSH-2.0-OpenSSH_8.2p1 Ubuntu-4ubuntu0.5
<21/07/2022 3:59:38 PM> FTP Session 27 XXX.XXX.XXX.XXX[Response] 500 Wrong command.
<21/07/2022 3:59:41 PM> FTP Server [Status] Session 27 ended gracefully.

Any help is much appreciated!