Measure with Summarize or GroupBy with Calculation and Filter??

Hi dbrandone  - can you try the below approach for Numerator. check it and let know

_RepeatNumerator =
VAR _MFMinDate = [_MonthsForwardMinDate]
VAR _MFMaxDate = [_MonthsForwardMaxDate]

-- Step 1: Get the customers with first purchase in the selected year
VAR _FirstPurchaseCustomers =
CALCULATETABLE(
VALUES(Orders[CustomerUID]),
Orders[FirstPurchaseYear] = SELECTEDVALUE('YearSelection'[Year])
)

-- Step 2: Calculate total completed purchases within the selected month range
VAR _OrdersWithinRange =
ADDCOLUMNS(
_FirstPurchaseCustomers,
"TotalCustOrders",
CALCULATE(
COUNTROWS(Orders),
Orders[OrderStatus] = "Completed",
DATESBETWEEN('Date'[Date], _MFMinDate, _MFMaxDate),
KEEPFILTERS(Orders[CustomerUID] IN _FirstPurchaseCustomers)
)
)

-- Step 3: Count customers with at least 2 completed orders
VAR _RepeatCustomers =
COUNTROWS(
FILTER(
_OrdersWithinRange,
[TotalCustOrders] >= 2
)
)

RETURN _RepeatCustomers

Hope it works. please check