One more time: Google font Enfold child theme

Hi,

i have found some threads, but no suitable solution.

I try to add a new google font to my enfold child theme.

I’m using this code in my functions.php:

add_filter( 'avf_google_heading_font', 'avia_add_heading_font');
function avia_add_heading_font($fonts)
{
$fonts['Roboto Slab'] = 'Roboto Slab:100,400,700';
return $fonts;
}

add_filter( 'avf_google_content_font', 'avia_add_content_font');
function avia_add_content_font($fonts)
{

$fonts['Roboto Slab'] = 'Roboto Slab:100,400,700';
return $fonts;
}

The font is selectable in the font settings tab at the bottom of the list. But it will not change on the site.

Thanks in advance

Alex