We use the Facebook Share option on a website with newsarticles. The website is build with PHP and uses Smarty. We generate a unique URL (stripped like /news/headline-of-the-article) and have the meta properties defined.
When the owner shares a links with an image that was previously uploaded, everything is fine. When he uploads a news image, inserts it into the article and shares, Facebook takes another pictures, the pictures that it finds first on the source-code. Altho, in the preview-box just before you publish, it shows the correct image. Once placed, it's the wrong one.
The Facebook Debug Tool shows as og:image tag > og:image domain/UserFiles/images/news/standard_14.jpg But when I look at the RAW tags og:image shows > domain/UserFiles/images/news/bosuil_1.jpg
So the og:image tag does it job and generates the correct URL, but facebook still posts the wrong image. When I force Facebook (manually) to scrape again, it shows everything good and also shares it correct.
I don't get it...