I had to manually add code from the fb developer section to my header.php AND install an open graph plugin.
Get facebook app ID by going through the steps here: https://developers.facebook.com/docs/platforminsights/domains
I had to click in the upper right corner to get started.
Then I had to add an “app” starting here, clicking on “websites”
developers.facebook.com/quickstarts/
Next page you name your “app” and hit “create” then you will have to choose a category and hit “create app id” next page you will find the code containing the app id. This code is then pastes at the beginning of the “body” section which in Intro theme was in the header (despite forums saying to look in page.php, single.php etc).
After this I installed “Facebook Open Graph, Google+ and Twitter Card Tags” plug in and entered both the app id and my fb user id (I created a specific fb account for this purpose having to verify with a phone# and everything – used google voice).
Now my posts are sharing correctly on Facebook. Phew!
