Shared posts on Facebook not displaying correctly

I am having similar problems with the free Magazine Basic Version: 3.0.7. I have used this theme for many years with success, but lately it is getting buggy and links to articles on FaceBook are posting very strangely. Rather than showing the image and an excerpt from the article, it is now just showing the URL to the main site (not the current article) and a bunch of gibberish in place of the article excerpt. I really like this theme and don’t really want to change it, so can someone help me to figure out why it is doing this?

Thanks,
Sandy
SellingtoGiftShops.com
[email protected]