I'm having an issue with the thumbnail / featured image, headline and og meta not showing up if I paste a link in FB with one specific post but not others. (Flushing the cache on FB doesn't work).
The site's on WordPress and the Yoast SEO plug-in should sort out the OG meta tags if you correctly enter your FB settings in the right section and I believe I have. I have also just pasted the code in my theme's functions.php
Here is my most recent blog post where it has no image nor headline: http://robcubbon.com/essential-wordpress-plug-ins-website/ – however it works on other posts
On the Debug tool it says: Must: "The 'og:type' property is required, but not present". But it's there : <meta property="og:type" content="article" />
It also says: Should: "The 'og:url' property should be explicitly provided, even if a value can be inferred from other tags." And it's there:
<meta property="og:url" content="link here" />
The OG Meta is exactly the same on this post (as far as I can see) as all other posts that have featured image and other meta info displaying properly in FB.
I would really appreciate if someone know why this is happening