This is happening in most cases due to the usage of the JetPack plugin which has the LazyLoad Option active.
The LazyLoad script will only run on page load, however, since the Blog Module pagination is using AJAX requests in order to load posts from page 2, 3, etc (without refreshing the page), the LazyLoad script will not run, making the images of the posts from page 2, 3, 4 to not show.
To fix that without deactivating the LazyLoad option, add this JS code to Divi ➤ Theme Options ➤ Integration tab ➤ Add code to the < head > of your blog:
<script>
(function($) {
$(document).ready(function() {
$( document ).ajaxSuccess(function() {
$(document.body).trigger('post-load');
});
});
})(jQuery);
</script>
That code will re-run the LazyLoad script once the AJAX request is completed and should fix the problem with the featured images not loading on older pages.