Segment Refresh, FAILS to refresh??

Question. When using the predefined Segments for an outbound mail, I click on the "REFRESH COUNT" and it never seems to refresh or update itself. Instead I am left with.. ((7,008 Recipients — Last Refreshed: 2 months ago Refresh Count)) What troubles me is that in my LEAST ENGAGES segment, there are ALWAYS several hundred people that seem to read each and every e-mail. But those names never seem to move OUT of the "Least" segment and up into the "Somewhat" segment, regardless of how often I e-mail them nor how often I click on REFRESH COUNT within each of the segments.. Suggestions???