You may want to go into site settings and turn down the suggested time interval, which defaults to 1 year, to something like 3 months so it is only suggesting more recent topics (when it can’t fill from new and unread).
You may want to go into site settings and turn down the suggested time interval, which defaults to 1 year, to something like 3 months so it is only suggesting more recent topics (when it can’t fill from new and unread).