Data discrepancy for Open Rate

Hi!

I’ve seen discrepancies between the Open Rate I calculate (since it is not available thru the API) and the one on the Klaviyo Platform.

The Open Rate on the Klaviyo platform for the month of October is 40.84%, as seen here below: 

However, when I use the data from the API to calculate the Open Rate, I do not get the same result. I tried with both the legacy versions of the API and the new one, and I get the same discrepancies.

The call I use to get the Metrics data is https://a.klaviyo.com/api/metric-aggregates
with the following body: 

{
    "data": {
        "type": "metric-aggregate",
        "attributes": {
            "metric_id": "Wzi5Ai",
            "interval": "month",
            "page_size": 500,
            "timezone": "UTC",
            "measurements": [
                "unique", "count"
            ],
            "filter": [  
                    "greater-or-equal(datetime,2023-10-01),less-than(datetime,2023-11-01)"  
               ]
        }
    }
}

So the results I get for each metric is:

Received Emails count 57562
Received Email unique 26526

Opened Emails count 39476
Opened Emails unique 15727

When I use the calculation from this link to get the Open Rate https://developers.klaviyo.com/en/docs/using_the_query_metric_aggregates_endpoint#open-rate-open_rate
I get either 68.58% for total open rate or 59.29% for unique open rate, but it is nothing near the value I get on the Klaviyo platform, which is 40.84%.

So I wonder where the discrepancy is coming from? Is there a way to get the same result?

Thank you,

Marie