It was wonderful to get such a varied and fast response to my issue. It turned out I somehow had two trees going within the same big tree at the same time (a duplicate merge was needed and all was where it should be). NOT a Family Tree glitch--just the usual user error. It was really puzzling for a time, as I had worked long and hard on a string of ancestors and they wouldn't show up in the tree view boxes. The smaller original tree kept popping up as the default I guess. All fixed!