Facebook share shows incorrect image

Is it just one particular post this is happening to?
I do know Facebook has a size limit on the images they include. I can’t remember the exact dimensions, but I think it is a minimum of 200x200px. Any less than that and it won’t show up.

Are you using an SEO plugin to specify exactly what image Facebook should use? If you aren’t, then Facebook is basically just trying to guess. It uses heuristics such as image size, name and location in the text to choose an image, but I’ve seen many sites where it guesses wrong.

The most reliable way is to use an SEO plugin to generate the appropriate metadata in your header so that Facebook knows what to display for each post.

It is happening to any post. I am using an SEO plugin and the OG:Tags are completely correct. However, the debug tool from FB now tells me the following:
“The ‘og:image’ property should be explicitly provided, even if a value can be inferred from other tags.” (basically for any OG tag).
This is weird. The OG tags are also properly set in my headers.

Edit: after fetching new scrape information, it is working correctly. Would I have to do this for every new post that will be made?

I think what happens by default is that when you create a new post, the first person who clicks share to Facebook won’t see the image because Facebook hasn’t scraped the page yet. Everyone else after that will see it because Facebook scrapes the page during that first share and caches the result.

So if you are concerned about that very first sharer not seeing the image, you could click share once yourself on all your new posts to make sure Facebook has scraped it.