sorting - Wordpress pre_get_post filter and sort by the same field -

i trying add filter , sort in pre_get_posts limit display posts having dates greater or equal today based on custom field (meal_date), , sort fields in ascending order using same custom field (meal_date). orderby works alone , filter works alone, not together.

add_filter('pre_get_posts', 'pre_get_posts_hook' ); // place pre_get_posts_hook in functions.php  $currentdate = date('y-m-t');    //today's date  function pre_get_posts_hook($wp_query) { //start pre_get_posts_hook     if(is_admin() ){ //if admin page     return $query; // take no action   }   if (is_archive()) //if archive page, following     {         $wp_query->set( 'orderby', 'meta_value' );  //set query orderby         $wp_query->set( 'meta_key', 'meal_date' ); // set query @ field         $wp_query->set( 'order', 'asc' ); // set query order ascending         $wp_query->set( 'meta_query', array( //start array               array(                     'key' => 'meal_date', //query meal_date field                     'value' => $currentdate, //when today's date                     'compare' => '>=', // compare equal or greater $currentdate                     'type' => 'numeric' // type of data compared                     )                     )                     );        return $wp_query;     } } 

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