Yes, that's what I'm mentioning.
Our developer also checked on this but we could not find any issue with our code in template: the open graph tags are correct because if something wrong with code of template, you can't have the correct image when sharing the URL directly in Facebook.
We also check directly via share button of Facebook : https://developers.facebook.com/docs/plugins/share-button/
and the same issue happens there - something wrong with FB's api here.
It's weird in this case but when you click post to facebook, the image appears correctly - this is the most important thing, right?