SSAS 2016 tabular : Discrepancy on countrows between measures visual studio vs Excel
The solution was to change the processing in Visual Studio (VS) from Default to Full.

The issue is described in detail here: https://connect.microsoft.com/SQLServer/feedback/details/685325/processing-ssas-in-tabular-mode-not-refreshing-data (see Cathy Dumas's reply under "Posted by Microsoft on 8/25/2011 at 2:02 PM")