In Cloudmin > virtualmin settings > virtual server backups > ..... the help text on the ssh destination has a wrong \ after the pass and before the @ for ssh. I had to remove the \ to get it to work. Ftp could be same way but I didn't test that one. Found the discrepancy by checking the cmd line API help text which showed no backslash. Been driving me nuts for months... lol. Backing up all domains from one place. Ahhh perfect now.
Wrong ssh://login:pass\@server/backup/domain.com.tgz
Correctionssh://login:pass@server/backup/domain.com.tgz
If ssh is not on 22, then ssh://login:pass@server:2222/backup/domain.com.tgz