I’m getting same problem.
http://kenliu.co.uk/a-quick-twitter-cards-test-with-kitties/
No metatags found
I’ve used a metatag validator, http://smo.knowem.com/
and for Twitter I’m getting 66.7% for Twitter tags, however, the open graph tags fallback are present
Have copied Jetpack generated tags
<!-- Jetpack Open Graph Tags -->
<meta property="og:type" content="article" />
<meta property="og:title" content="A quick Twitter cards test with kitties" />
<meta property="og:url" content="http://kenliu.co.uk/a-quick-twitter-cards-test-with-kitties/" />
<meta property="og:description" content="Just testing Twitter cards integration with Wordpress..." />
<meta property="article:published_time" content="2015-04-07T08:58:33+00:00" />
<meta property="article:modified_time" content="2015-04-07T08:58:33+00:00" />
<meta property="article:author" content="http://kenliu.co.uk/author/kenwen/" />
<meta property="og:site_name" content="Ken Liu" />
<meta property="og:image" content="http://kenliu.co.uk/wp-content/uploads/2015/04/photo_22517_20120922-300x225.jpg" />
<meta property="og:image:secure_url" content="https://i2.wp.com/kenliu.co.uk/wp-content/uploads/2015/04/photo_22517_20120922-300x225.jpg" />
<meta property="og:locale" content="en_GB" />
<meta name="twitter:site" content="@kenhliu" />
<meta name="twitter:image" content="http://kenliu.co.uk/wp-content/uploads/2015/04/photo_22517_20120922-300x225.jpg?w=1400" />
<meta name="twitter:card" content="photo" />
<meta name="twitter:creator" content="@kenhliu" />