I have the problem when a view has more than one displays. When I show a display as views calc table and the default display has a contextual filter where i set the option to show no results behavior if the contextual filter is not given, the view to calculate the table summary is always the default view. In my case this view returns no result because there is no argument given.
I should be better to execute the correct display to calculate the table. Otherwise, if there is no result as in my case there will be no summary in the table footer.