[AvidEreader]

I'm not sure what I did but when I use a tag to filter Calibre, it simply highlights the relevant books in the list rather than stripping the list of all other books. The only way to remove the books is to use the "Restrict to" button and click on current search. Previously when I clicked on a tag, it filtered to those books (green plus), then excluded all those books when I clicked again (red minus). The green and red icons are there but the list still includes all books. Can someone help me to figure out what I may have done to cause this change? I have hundreds of ebooks and really need to use the tag filter feature.