title: WP_query category__in array only pulls from first category id
body: <p>I am trying to get ALL post id's for posts in these categories (relation OR): 10,11,12,13,14 with certain extra attributes. My problem is with the categories however.</p>
  
  <p>My args array for my wp_query is as follows: </p>
  
  <pre><code>$args = array(
                          'orderby' =&gt;'ID',
                          'post_type' =&gt; 'post',
                          'post_status' =&gt; 'publish',
                          'posts_per_page' =&gt; -1,
                          'category__in' =&gt; array('10','11','12','13','14'),
                          'meta_query' =&gt; array( 
                                      'relation' =&gt; 'AND',
                                      array(
                                       'key' =&gt; 'joke_type',                 
                                       'value' =&gt; $type,                 
                                       'type' =&gt; 'CHAR',                 
                                       'compare' =&gt;  '='
                                   ),
                                       array(
                                           'key' =&gt; 'joke_rating',
                                           'value' =&gt; 3,
                                           'type' =&gt; 'SIGNED',
                                           'compare' =&gt; '&gt;='
                                       )
                           ),
                           'fields' =&gt; 'ids' 
                  );
  </code></pre>
  
  <p>This only gets me posts from category 10 (or whichever ID I place first in the array). I also tried: <code>'category__in' =&gt; '10,11,12,13,14'</code> and <code>'category' =&gt; '10,11,12,13,14'</code> and <code>'cat' =&gt; '10,11,12,13,14'</code> All act the same.</p>
  
  <p>Any idea why this could be happening?</p>