Google Fonts not showing on mobile, and some Desktops

Hi

I have gone through numerous threads and cannot seem to find the topic related to my Question,find it quite strange that on one esle picked up on this.

For some reason Google fonts added through the Functions.php page does not work on mobile phones (ios) and some desktops.

add_filter( ‘avf_google_heading_font’, ‘avia_add_heading_font’);
function avia_add_heading_font($fonts)
{
$fonts[‘Oswald’] = ‘Roboto:100,400,600,800’;
$fonts[‘Roboto Slab’] = ‘Roboto Slab:400,300,700’;
return $fonts;
}

add_filter( ‘avf_google_content_font’, ‘avia_add_content_font’);
function avia_add_content_font($fonts)
{
$fonts[‘Oswald’] = ‘Open Sans:100,300,700’;
$fonts[‘Roboto Slab’] = ‘Roboto Slab:400,300,700’;
return $fonts;
}

So I tried to enqueue the script as follows but when I inspect the head the “,” separating the font-weight are replaced with % signs.

function load_fonts() {
wp_register_style(‘googleFonts’, “https://fonts.googleapis.com/css?family=Roboto+Slab:400,300,700,100”, false);
wp_enqueue_style(‘googleFonts’);
}
add_action(‘wp_enqueue_scripts’, ‘load_fonts’);

in my style.css i would then call the style .something { font-family: ‘Roboto Slab’, serif;}

Can anyone please assist me in this please

Regards