When I Share a link to my Facebook page from my classified sites it does not pass any thumbs or info to the Share Link - only the listing heading.

I've only now noticed that this has stopped working properly - It use to send the thumb as the Facebook page should show.

Here's a link to my Listing and then to the Facebook Page that has the link to the listing - note no thumb just the heading. The older Shared Links have a thumb but the new one only has the heading. This happens with both my Classified sites.

Anyone got any idea how to fix this?