Thanks a lot. It worked!
It also solved the ssh-copy-id issue (mkdir: cannot create directory ‘.ssh’: Permission denied) described here: HestiaCP permissions issue
Not very important, but just a suggestion. CyberPanel allows to add ssh keys and change ssh port in the web interface. It might be a good idea to implement, since most newbies don’t know how important these things are to make the server more secure.
Or just an editor in the web interface for the sshd_config file to quickly change the ssh port, disable root login and password authentication.
Anyway, I’m very happy with HestiaCP working on Debian 10. Thanks again!