Intel Customer Support is looking into this issue and I will get back to you as soon as possible.
I apologize for the inconvenience you are having with this product and I hope we can provide a solution or at least an explanation for the issue.
You already know that LightDM* is the display manager running in Ubuntu. It starts the X servers, user sessions and greeter (login screen). The default greeter in Ubuntu is Unity Greeter
If you have any further questions I would recommend that you go directly to Canonical*. Here is the home website: Canonical | The company behind Ubuntu