Recent Facebook News Feed changes can be super confusing.
More importantly, you need to make sure that you are following established Facebook guidelines when it comes to the pictures you post, because that can also mean if people see your post.
Facebook recommends a specific image size and aspect ratio for images appearing in link posts:
Use images that are at least 1200 x 630 pixels for the best display on high resolution devices. At the minimum, you should use images that are 600 x 315 pixels to display link page posts with larger images.
Images smaller than 600 x 315 pixels appear as a thumbnail next to the headline instead of above the headline. For non-thumbnail images, Facebook recommends sticking as close to the 1.91 aspect ratio as possible. That’s how you avoid awkward automatic crops by Facebook. If you don’t like the photo Facebook automatically pulls from the article you’re linking to, you can always upload another one with a different crop after the link preview has been generated.