Truncate Title & Breadcrumb

Hey evas49,

Thank you for the inquiry.

You can try this filter in the functions.php file to truncate the breadcrumb trails.

function avia_breadcrumbs_trail_mod($trails)
{
    $newtrails = [];

    foreach ($trails as $key => $trail) {
        $oldLabel = strip_tags($trail);
        $newLabel = substr($oldLabel, 0, 10).'...';

        $newtrails[$key] = str_replace($oldLabel, $newLabel, $trail);
    }

    return $newtrails;
}

add_filter('avia_breadcrumbs_trail', 'avia_breadcrumbs_trail_mod', 50, 1);

For the title, you can try this code.

function max_title_length( $title )
{
    $max = 35;
    if( strlen( $title ) > $max ) {
        return substr( $title, 0, $max ). " …";
    } else {
        return $title;
    }
}

add_filter( 'the_title', 'max_title_length');

You also incorporate the wp_is_mobile function if you want to only apply it on mobile view.

// https://developer.wordpress.org/reference/functions/wp_is_mobile/

Best regards,
Ismael