Perhaps this is a known bug? If I go to the Tags view, and select a particular tag, I get a list of, say, 8 pdfs. If I then go to another pdf document that is not in this list, and add this tag to a page, and return to the filtered list, the recently added document does not appear there. Unselecting and selecting again does not help either. I have verified that rebooting helps, but that's kind of overkill method. But I haven't found another way to update this tag index.
Have others also experienced this?