Have a bit of a head scratcher which I'm sure has a relatively simple answer which I'm not quite seeing!
I have created a very simple funnel which looks at two segments of grouped pages. The segments are all set on a hit level and use prop variables. The funnel itself is set on a visitor level, because we want to see funnel activity across multiple visits, and set to capture all data over the last four months.
So then I've broken down the funnel itself, one using the Month dimension and choosing February (in green below) and one using the time period 'Last month' (in blue). Last month being February, of course. So, my question is... why are the two values different? Is there a difference in the way these are processed that could have an impact?