MAximizing doesn't maximize

Hi,

   I have an executable buit il LabVIEW 2017 running on a Win10 PC.
The apparence of the main VI is as ttached picture

And the windows runtime posizion is Maximized

I expect the front panel to occupy the whole desktop area, but I get a window That miss almost 10px on every side. And it is a moveable window, so it is not maximized...

What can it be due to?
Thank you.

P.S. If I Allow user to resize window, it take the whole sceen (except maybe a single pixel) but I don't want the user to resize the panel...