If i understand correctly, you are trying to get all the posts within “Contact Data” category and order those posts by the acf field “region_contacto”.
The way you run the query will not work, because the sorting will only happens inside each query.
If you want the posts to be sorted by the acf field, they should be within the same query, like so:
<?php
$news_cat_ID = get_cat_ID('Contact Data');
$news_query = new WP_Query( array(
'posts_per_page' => -1,
'cat' => $news_cat_ID,
'meta_key' => 'region_contacto',
'orderby' => 'meta_value',
'order' => 'ASC',
));
while ( $news_query->have_posts() ) : $news_query->the_post();
echo get_field('region_contacto') . '<br/>';
endwhile; wp_reset_query();
This should give you all the posts inside “Contact Data” category and ordered by the acf “region_contacto” value.
Cheers
