Issue with measure values in PowerBI: Discrepancies between row-level and aggregated values

Question

In Power BI, I'm encountering discrepancies in my measure values between row-level and aggregated views of my data. When I don't summarize the balance column in my table, each row displays the correct value for my measures. However, when I summarize the balance column to show totals, the measure values (Balance Change and Paid Off) for the total are not correct. How can I ensure that my measures behave consistently, whether the balance column is summarized or not.

Here are both of my measures that I am using as columns in my table.

PaidOff = 
VAR PreviousMonthBalance =
   CALCULATE(
       SUMX(FILTER(Query1,Query1[act_end_bal] > 0),
           Query1[act_end_bal]),
       PREVIOUSMONTH(Query1[analysis_date]))
VAR CurrentMonthBalance =
   CALCULATE(
        SUMX(FILTER(Query1,Query1[act_end_bal] > 0),Query1[act_end_bal]),
       Query1[analysis_date] = MAX(Query1[analysis_date]))
RETURN
   IF( CurrentMonthBalance = 0, PreviousMonthBalance, 0)

and

Balance Change = 
VAR CurrentMonthBalance = SUM(Query1[act_end_bal])
VAR PreviousMonthBalance = CALCULATE(SUM(Query1[act_end_bal]),PREVIOUSMONTH(Query1[analysis_date]))
RETURN
IF(PreviousMonthBalance > 0 && CurrentMonthBalance > 0, CurrentMonthBalance - PreviousMonthBalance, 0)