Issue with USERELATIONSHIP DAX function when querying Analysis Services from PowerBI

I have a Tabular data model with [Calendar] and [Incidents] data sets. The [Incidents] data set has [Create Date] and [Resolve Date]. I create a relationship for [Calendar].[Date] -> [Incidents].[Create Date] (this is marked as active) and a relationship for [Calendar].[Date] -> [Incidents].[Resolve Date] (marked as inactive). I then create 2 measures; Created and Resolved. Both use the CALCULATE and USE RELATIONSHIP functions e.g. Created:=CALCULATE(sum([Incidents],USERELATIONSHIP('Incidents'.[Create Date] = 'Calendar'.[Date]). The results are perfect when querying the Tabular data model via Excel. However, PowerBI will not show the correct totals for the Inactive relationship when there are more than say 20 items in the visual. e.g. if you want a tabular visual that shows Resolved by [Assigned Group], and there are 50 assignment groups, the total is < than actual total. I have tried to replicate with the same data in SQL and Excel and it works just fine. Only Tabular data models are the problem. Please help