My shadow slider is broken. For the image I'm working on, moving it rightward lightens the shadows in the Develop module as it's supposed to. But when I switch to the Library module the image reverts and the shadows actually go darker than they were in the original image. Similarly, when I lighten the shadows in the Quick Develop section of the Library, the shadows (and seemingly the whole image) darken. The image had many other changes, such as B&W conversion, that "stuck" but for some reason the slider slider makes things darker no matter what direction I move it, right or left. The changes only look correct as long as I'm in the Develop module.
Thanks, I've been having other glitchy things happen so I'll try it. In the meantime, I solved it for this image by redrawing the preview via the Library menu. Exporting and using the publish feature worked fine before I did this, so it seems to be something in the catalogue preview for that image. Just thought I'd share this workaround in case anyone else experiences the same problem.