Tags not showing

I have some 80 BookMarks that are Tagged and Bundled, but since
yesterday BookMarks older than 6 days are not showing when I click on
a Tag. The Tag still says (e.g.) "Showing all 7 items" but only 4 are
listed. Happens on all Tags, and it is consistently only showing Links
added in the past 6 days.
The full Bookmark view shows all 80, and they all appear to have the
correct Tags.
Am I missing something?