WP_Query that targets all categories

It’s hard to say exactly why adding the category changes anything, but… The query looks OK… Almost… There are some things that concerns me:

  1. 'post_type' => 'posts', – there is no built-in post type called posts. You should use post in there, unless it’s your CPT (but then… I don’t think it’s a good name ;))

This is the biggest concern. But there are some minor ones also:

  1. 'posts_per_page' => '4', – it should be a number, it will be converted, but why should it have to…
  2. 'nopaging' => false, – it’s default value for this arg, so there is no point of setting it.