DAX help: calculating the ratio of categorial variables

I have trouble counting the ratio of categorial variables in table over a certain time period.

Let's say I have sales data in a table called "purchases", and I want to calculate the ratio of returned goods. Each row in the table represents a sales transaction of a certain product to certain customer. There's a column called "status" which has a categorial variable (number) which tells the status of the purchase, a value of "3" meaning a returned purchase. I want to visualize the ratio of returns in all sales transactions over a time period, and be able to slice it by customers, item category, etc.

I'm able to count the number of rows with certain status, but not able to calculate the ratio. I tried two different DAX expressions, and they both result in the same incorrect result: all bars in the visualization say that the ratio is 1, but the bars appear otherwise. Any help is appreciated.

ratio = 
	CALCULATE(
		COUNT(purchases[purchase_id]),
		FILTER(purchases, purchases[status] = 3)
	)
	/
	CALCULATE(
		COUNT(purchases[purchase_id),
		FILTER(purchases, purchases[status] <= 4)
	)

ratio = 
    SUMX(
         purchases, 
         IF(purchases[status] = 3, 1, 0)
    ) / 
    SUMX(
        purchases,
        IF(purchases[status] = 1
           || purchases[status] = 2
           || purchases[status] = 3
           || purchases[status] = 4
           , 1, 0
    )
)