Sums are not calculating correctly

[whodis118]

I have a measure that is supposed to calculate the sum of a given column, but it is not working correctly. I can only speak to when the report is filtered, since I cannot export more than 30k rows....

My measure goes like this:

Taxes = CALCULATE(SUM(EquipmentCostRevenue[EQ Cost]),EquipmentCostRevenue[Parent Cost Code] ="Property Tax")

When I export the data to excel, I can use excel's sum function, and the sums are added up correctly. In Power BI, the sum is calculated inaccurately and is lower than it should be.

Is the problem with my dax measure here? What is needed for someone to help me with this?

[Greg_Deckler]

@whodis118 I answer like 3 of these a day. Vote for this idea: Microsoft Idea (powerbi.com)

This looks like a measure totals problem. Very common. See my post about it here: https://community.powerbi.com/t5/DAX-Commands-and-Tips/Dealing-with-Measure-Totals/td-p/63376

Also, this Quick Measure, Measure Totals, The Final Word should get you what you need:
https://community.powerbi.com/t5/Quick-Measures-Gallery/Measure-Totals-The-Final-Word/m-p/547907