I’ve remedied this problem with a css fix. Basically setting the display of the featured image on the featured post to none. Then when that featured post is replaced with another, and it goes into the teaser grid, boom the image shows up. SolanosKitchen, looking at your site and theme, you’d use something like
.feature img.post-image {
display: none;
}
Basically, the featured images have a different class than the standard images from displaying the full post contents. You have to determine what that unique class is and hide it with CSS, hope this helps someone.