Impossible to get a ssh connection to anaconda when using sshpw options in grub command.

I am trying to install f23 TC1 on ppc64le VM 
http://ppc.koji.fedoraproject.org/compose/23_TC1/23_TC1/Server/ppc64le/iso/Fedora-Server-DVD-ppc64le-23_TC1.iso
using following grub command:
linux /ppc/ppc64/vmlinuz inst.sshd sshpw --username=test testpassw0rd --plaintext;
initrd /ppc/ppc64/initrd.img;
boot

When I get to the following panel:

Starting installer, one moment...
anaconda 23.19.6-1 for Fedora 23_TC1 (pre-release) started.
 * installation log files are stored in /tmp during the installation
 * shell is available on TTY2
 * if the graphical installation interface fails to start, try again with the
   inst.text bootoption to start text installation
 * when reporting a bug add logs from /tmp as separate text/plain attachments
13:06:18 X startup failed, falling back to text mode
================================================================================
================================================================================
VNC

X was unable to start on your machine.  Would you like to start VNC to connect t
o this computer from another computer and perform a graphical installation or co
ntinue with a text mode installation?

 1) Start VNC

 2) Use text mode

  Please make your choice from above ['q' to quit | 'c' to continue |
  'r' to refresh]:

I try to connect thru ssh to the VM machine using "ssh test@vm55"
and it fails with "Permission denied, please try again."
Using "ssh root@vm55" succeed...

Note that in syslog, there is:
12:36:27,212 ERR sshd: error: Could not load host key: /etc/ssh/ssh_host_dsa_key
but it seems not linked to the problem:

[anaconda root@vm55 tmp]# ls -al /etc/ssh/ssh*key
-rw-r-----. 1 root ssh_keys  227 Oct 20 12:41 /etc/ssh/ssh_host_ecdsa_key
-rw-r-----. 1 root ssh_keys  387 Oct 20 12:41 /etc/ssh/ssh_host_ed25519_key
-rw-r-----. 1 root ssh_keys 1675 Oct 20 12:41 /etc/ssh/ssh_host_rsa_key

[anaconda root@vm55 tmp]# ssh-keygen -t dsa -f /etc/ssh/ssh_host_dsa_key

[anaconda root@vm55 tmp]# ls -al /etc/ssh/ssh*key
-rw-------. 1 root root      672 Oct 20 12:46 /etc/ssh/ssh_host_dsa_key
-rw-r-----. 1 root ssh_keys  227 Oct 20 12:41 /etc/ssh/ssh_host_ecdsa_key
-rw-r-----. 1 root ssh_keys  387 Oct 20 12:41 /etc/ssh/ssh_host_ed25519_key
-rw-r-----. 1 root ssh_keys 1675 Oct 20 12:41 /etc/ssh/ssh_host_rsa_key

[anaconda root@vm55 tmp]# chgrp ssh_keys /etc/ssh/ssh_host_dsa_key
[anaconda root@vm55 tmp]# systemctl restart sshd 

ssh root without password still succeed when ssh test@vm55 still fails