Hi, George. Thanks for looking into this and replying. I did the fix that @sterndata recommended, and that fixed the issue of images not appearing on the site. I have blocked the direct access to the image URLs deliberately, but I’ve allowed access to the images for the site domain, so I think it all looks good now.
There is the little issue of JPGs not uploading to the media library correctly now, but that’s a separate issue, and I found a kluge for that.
Thanks again.