Custom post types not imported properly

I’ve registered a custom post type:

function create_gallery_post_type() {
  register_post_type( 'sim_gallery',
    array(
      'labels' => array(
        'name' => __( 'Sim Gallery' )
      ),
      'public' => true,
      'has_archive' => true,
      'menu_position' => 10,
      'description' => "Post for displaying gallery"
    )
  );
}

Now I’m trying to import the content from my staging server to my dev server.
During the import process, I get the feedback that it failed to import all my custom post.

So clicking ‘Sim Gallery’ in the left navigation panel, shows zero posts.

But if I look at the database, wp_posts, I can actually see the posts.
If I try to create a post with a name that is already registered, I get somename-2 where -2 indicates that a post by the same name is already registered.

So my question is:

1) Why does the wp import function say that it failed to import my cistom posts?
2) Why are my custo mpost not shown in the post listing in the backend?

Have you tried removing the underscore from your Custom Post Type name? I ran into an issue a few weeks ago that was resolved when I changed to only alphabetical characters.