OpenNebula 5.0.2 and 5.2 - VMs VNC doesn't work after stop/resume or suspend/resume

Hi Guys,
VMs VNC after stop/resume or suspend/resume doesn’t work anymore.
If I try to open the VNC I get : "VNC Authentication failed."
Same error with a VNC client.

Here what reports novnc.log:

[13/Oct/2016 08:51:51] connecting to: myhost:6843
[13/Oct/2016 08:51:52] code 400, message Bad request syntax (’\x88\x80tM\xc41’)

I tried to launch the following command on the host and seems the password is disappeared.

virsh domdisplay --include-password 78


The problem is present also on OpenNebula 5.2

I am also facing the same problem. Is anyone aware of the solution?