generate_logo filter on mobile

Hi guy's,

I'm using the generate_logo filter to change the logo on a specific category.

This works like a charm on desktop but does not seem to work on mobile/tablet. Any ideas?

The code i'm using:
add_filter( 'generate_logo','tu_category_logo' );
function tu_category_logo( $logo )
{
if ( is_category('slug') || in_category('slug') ) {
return 'url to logo';
}
return $logo;
}