I have the same problem too. When my post shares with FB and Google+, on the initial posting, many times FB will post the image when Google+ does not. thelazygeeks.com has been having this issue randomly. This post, that posted earlier today
https://thelazygeeks.com/disney-re-airing-star-wars-rebels-on-abc/
Posted correctly on our FB on its initial scrap but did not on Google+. Yet the posts before and after that came up correctly. I made the post and hit ‘Schedule’ and never touched it again. On occasion, it will happen to both FB and Google+, but more often than not it mostly happens to Google+.
When it does happen, it is the same as the person who initiated this post. Pictures do not appear. I use the debugger, scrap the url and its there. When I manually post on both, the image appears. I don’t want to have to keep repairing the posts that do not show up correctly.
Thanks you.