This is happening because the parent theme is calling in styles.css using enque.
Disable it by adding the following into the child themes functions file:
/* -- Removes the parent theme stylesheet,
to stop it being called twioce (Foundation CSS was being called after style.css)
-- */
function PREFIX_remove_scripts() {
wp_dequeue_style( 'screen' );
wp_deregister_style( 'screen' );
wp_dequeue_script( 'site' );
wp_deregister_script( 'site' );
// Now register your styles and scripts here
}
add_action( 'wp_enqueue_scripts', 'PREFIX_remove_scripts', 20 );
/* -- Removes the parent theme stylesheet END -- */