Getting equal quartiles from a ranking

I have a list of around 80.000 customers. I`m trying to rank them based on how often they have purchased. For this I've created a calculated column called Frequency. This is basically just a count of all orders. 

What I want to achieve is rank the customers based on this and then put them in equal quartiles based on their ranking. So Q1 has 20.000 customers, Q2 has 20.000 customers etc..

To achieve this I`m following this example: https://community.powerbi.com/t5/Desktop/quartile-ranking/m-p/560850?collapse_discussion=true&filter=location&location=forum-board:power-bi-designer&q=quartiles&search_type=thread

I created a measure called Frequency Rank. And that works fine. But when I use the  code to create the quartiles the visual I`m using the Frequency Quartile measure in just keeps loading forever

Frequency Rank = 
RANKX ( ALL ( magentoCustomers[customerID] ), CALCULATE ( SUM ( magentoCustomers[Frequency] ) ) )

Frequency Quartile = 
VAR _table =
    SUMMARIZE ( ALL ( magentoCustomers ), magentoCustomers[customerID], "_Rank", [Frequency Rank] )
VAR _table1 =
    ADDCOLUMNS ( _table, "_Rank1", RANKX ( _table, [_Rank] ) )
VAR Percentile25 =
    PERCENTILEX.EXC ( _table1, [_Rank1], 0.25 )
VAR Percentile50 =
    PERCENTILEX.EXC ( _table1, [_Rank1], 0.5 )
VAR Percentile75 =
    PERCENTILEX.EXC ( _table1, [_Rank1], 0.75 )
RETURN
    IF (
        [Frequency Rank] < Percentile25,
        "Q1",
        IF ( [Frequency Rank] < Percentile50, "Q2", IF ( [Frequency Rank] < Percentile75, "Q3", "Q4" ) )
    )

Example data set: