Opennebula 5.0 ssh passwordless issue

We have installed Opennebula 5.0 on Ubuntu server 16.04. It works fine but we cannot add a node to the front end because it asking for a password.
Openebula 4.14 on Ubuntu 14.04 is very easy to install and adding nodes without asking for a password works great.
We following these instructions to install version 5.0 but no luck to add any nodes without asking for a password.
Can someone please give me a hand on this.
Many thanks in advance.
Our HW:
4x Dell Poweredge R710 server
1x HP Proliant ML350p gen 8 server


I think you should check your SSH connection on sunstone server to kvm node: Login to oneadmin user by ssh and ssh into kvm node, and from kvm node ssh into sunstone server. Read carefully step 4: