IN the "social" tab of my blog posts I always add an image in the "Facebook image" field which i would like to show up when i post a link to the blog post on Facebook. Otherwise, Facebook just shows the background image of my site.
Sometimes the image which should override my site's background image does show up in Facebook, but very often it doesn't. I don't understand, because the "og:image" tag in the source code always contains the correct image.
Can somebody explain what could be wrong?