Yup. Update: the expected file paths do work in the browser. Not sure why that didn’t work before. But, in one site I still have the problem of the images being broken or not displaying at all in the media library.
BTW: I used a “cloner” to create several subdomains. I first created a subdomain that had quite a few images in the library and then cloned it several times. I then deleted the images on the server in all but one clone. But now they don’t show up properly in that clone. They are definitely on the server.
I uploaded some new images into the other sites and those seem to work properly and are displayed and available to plugins. It’s just that one remaining clone site with the original images, not the main site, that is frustrating me. I suppose I could try downloading and then re-uploading.
That might work.