Row total count and grand total count is diffrent by using DistinctCount and Calculate in Matrix

[Anonymous]

I am actively looking for the solution to resolve the issue appeared several times in my Power BI report. So I have created the measure to calculate the distinct count of the users which are connected City/country-wise by using below DAX.

Total User Connected(Wireless) = CALCULATE( DISTINCTCOUNT('Posture assessment'['ENDPOINT_ID']),FILTER('Posture assessment','Posture assessment'[NAC Policy ]="Wireless"))

And my grand total and subtotal is completely wrong as compared to actual row count. Then I tried a different approach with this DAX below but no change. Total is still wrong.

Count of Unique = SUMX(Values('Posture assessment'[Region]),CALCULATE(DISTINCTCOUNT('Posture assessment'['ENDPOINT_ID']),FILTER('Posture assessment','Posture assessment'[NAC Policy ]="Wireless")))

Table illustration is: Here, for example, India's value is different as compared to the total.

[amitchandak · Accepted solution]

@Anonymous , Try to rollup from city level

Count of Unique = SUMX(summarize('Posture assessment','Posture assessment'[Region],'Posture assessment'[Country],'Posture assessment'[City],"_1",CALCULATE(DISTINCTCOUNT('Posture assessment'['ENDPOINT_ID']),FILTER('Posture assessment','Posture assessment'[NAC Policy ]="Wireless"))),[_1])

[Anonymous]

Thanks for the quick help Amit, It is working. 

Just wanted to know why we are using "_1". Is this to calculate row or some kind of indexing. 

Please explain.