Text in popup appearing as excerpt

This is a very odd issue that might be hard to understand, and it is very difficult to know what is causing it, and I should add that I am not saying your plugin is. I created an ad in Facebook to promote my site, but instead of running it as an ad, I created a post from it. The post included the call to action button ‘Learn More’ which takes anyone who clicks it to my site. However, alongside the button is the usual things – name of the website and what should be (I assume) is the excerpt or first few lines of text from the page; but what is appearing are the lines from a popup I created, and it is not even a popup that appears on the url linked to, or one that should appear to logged out users.

I have tried creating excerpt text for the page in question, and in that popup have changed the Display Rules to never show it on that page, or to logged out users, but neither have had any effect. I have tried changing settings in the Facebook Ads Manager relating to this ad post but that also doesn’t change anything (unless cached versions aren’t clearing on Facebook when browser cache is cleared).

Have you encountered this before and do you have any ideas or suggestions how to avoid this happening? I suspect it is a Facebook issue but my efforts to get any suitable response, or any response at all, so far have failed.