I’ve imported Josefin Sans from Google Fonts by adding it to wp-includes/functions.php:

function load_google_fonts() {
  wp_register_style('googleFonts', 'https://fonts.googleapis.com/css2?family=Josefin+Sans:wght@100;200;300;400;500;600;700&display=swap');
  wp_enqueue_style( 'googleFonts');
}
add_action('wp_print_styles', 'load_google_fonts');

and assigning it to a selector in the customizer:

* {
    font-family: 'Josefin Sans';
    font-weight: 600;
}

font-weight values of 400 and above are displayed correctly but values of 300 and below seem to be displayed as 100. See font-weights from 600 to 100:

Anything I can do about it?