why does the final forecast continue to be calculated after the end of lifecycle date

We have entered end dates manually into the Demantra worksheet, and can see that the end dates are populated for the various Sales Channels and Orgs.  However, for one of the Sales Channels, the final forecast continues to be calculated, even after the end of lifecycle date that was entered - the other Sales Channels are working as expected, ie final forecast drops to zero at the end date.  We also use a WebADI to enter end dates in bulk, and for this we populate the Item, Sales Channel, Org and Country levels, and the end date.

When we look into the levels below the Sales Channel and Org, we can see that some of the Regions don't have the end date populated, and so the final forecast does not reduce to zero as we would expect.  Our location level hierarchy is : Top level = Sales Channel / Org / Country / lowest level = Region.  We produce forecast at the Country level.