[Plugin: Cleaner Gallery] How to add image description/title/caption?

I have this same problem. I’m able to get image captions by setting the checkbox for “Use image title as caption if no caption is available” in the Cleaner Gallery Settings panel. But I’m not able to intentionally set a caption for an image; in a Post or Page’s WordPress Image popup I have filled in the Title, Alt, Caption and Description fields but none of them show up as a caption for the Lightbox popup except the title by default. However, using the title is not satisfactory if the caption should be a sentence.

Any suggestions?