@xfrocks, I have done some tests latelly and I think that the issue belongs to the addon.
My addon is sharing normally but it never shared with the images on og:image. YEsterday I saw that the default xenforo was set and them I replaced to the logo of my forum,. I just made a test now and when the addon shares, it still skipes the logo but when I enter to the page on facebook and paste a link, the logo enters normally.
Check the attachment. Firstly the topic was created, the addon shared it with no image. I just made some adjustments to the thread and shared myselft the link on the page ( pasted link, wait load the box, put some text and then removed the link and posted).
As you can see, the og:image is working but no with the addon