Hi Ian,
EasyBlog's listing page does not specify any opengraph image for Facebook to use, which Facebook then uses their best guess(
https://take.ms/pr0Yo).
However, I notice on your page that opengraph image is specified(
https://take.ms/vn46M). I'm not sure why this is the case and would need to check on your backend of the site to be sure.
Perhaps you currently have a third party extension that does this and if this is the case, then it may also be possible for that extension to specify a different opengraph image.
Can you provide us the backend access to that site so we can check it out?