Featured Image on custom post not displaying right with new images

I administer a site built by a designer (not me) using a custom theme, etc. I’m not half so clever as they were! The home page (seen at akenergyefficiency.org ) has a sliding banner near the top (Invest In Improvements and Go Green and Make Some Green), and I have been tasked with making new banners to replace the existing ones. This should not be difficult.

The banners are a custom post type using the pods plugin, with ‘featured image’ enabled. I have been unable to get my newly uploaded images to display on the banners (either new banners I make or the old banners already up). I can use the already uploaded old banner images on new banners and they work fine. If I use my newly uploaded images the text displays perfectly, but the featured image displays as the image name in blue in the corner and the blue square with question mark in the center.

I am making the images the same pixel size (1400×325) , approximately the same kb (45ish), and the same file type (jpg) as the old images that work. In fact, I can download the old image and re-upload it with a slightly changed file name and the old image will work in the post/banner while the newly uploaded (but same) image will not. The featured image in all cases appears fine in the edit window for the post, and if I paste the image in the test box of a regular post it shows up just fine.

The site has recently been migrated to a new server, but all the uploads folders, old and new, seem to have the same permissions (I checked to see if maybe the upload folders created since the move have restricted permissions. They seemed to on a cursory inspection). The fact that the old image, newly uploaded, doesn’t work seems consistent with something wrong with the file permissions for new folders, but the new images displaying fine in the body of a regular post seems to contradict that.

I can copy over the code for displaying the post type on the home page and the pertinent css if that seems useful.

So what am I missing? What is different about the old and new images that I’m not thinking to check for? Or what???
Thanks!!!!