Create Event API does not work as expected since revision v2023-07-15

Currently, I am using API revision v2023-06-15, and everything works fine for me in this revision.

However, I want to upgrade my service to use the latest stable revision (v2024-02-15), but it seems it does not work as expected.

The functionality of the APIs (Client and API) to create new events in Klaviyo within revision v2023-06-15 is particularly advantageous. In this version, a single request can achieve the following actions:

• Create or update a profile based on External ID, Email, and/or Phone Number.
• Create an event and link it with the respective profile.

However, it's worth noting that with the newer API revisions, despite the request returning a successful status code 202 Accepted, the event and profile are not created or updated as expected.

Example using revision v2023-06-15 (working):

curl --request POST \
  --url https://a.klaviyo.com/api/events/ \
  --header 'Accept: application/json' \
  --header 'Authorization: Klaviyo-API-Key XXXXXXXXXX' \
  --header 'Content-Type: application/json' \
  --header 'revision: 2023-06-15' \
  --data '{
    "data": {
        "type": "event",
        "attributes": {
            "metric": {
                "name": "Custom Event Name"
            },
            "properties": {
                "custom": "Custom Event Property",
                "value_currency": "USD"
            },
            "value": 10,
            "profile": {
                "$email": "email@example.com",
                "$id": "ExternalProfileID",
                "$first_name": "John",
                "$last_name": "Doe",
                "any": "Custom Profile Property"
            }
        }
    }
}'

Example using the latest revision v2024-02-15 (not working):

curl --request POST \
  --url https://a.klaviyo.com/api/events/ \
  --header 'Accept: application/json' \
  --header 'Authorization: Klaviyo-API-Key XXXXXXXXXX' \
  --header 'Content-Type: application/json' \
  --header 'revision: 2024-02-15' \
  --data '{
    "data": {
        "type": "event",
        "attributes": {
            "metric": {
                "data": {
                    "type": "metric",
                    "attributes": {
                        "name": "Custom Event Name"
                    }
                }
            },
            "properties": {
                "custom": "Custom Event Property"
            },
            "value": 10,
            "value_currency": "USD",
            "profile": {
                "data": {
                    "type": "profile",
                    "attributes": {
                        "email": "email@example.com",
                        "external_id": "ExternalProfileID",
                        "first_name": "John",
                        "last_name": "Doe",
                        "properties": {
                            "any": "Custom Profile Property"
                        }
                    }
                }
            }
        }
    }
}'

API documentation:

• Create Event API v2023-06-15
• Create Event API v2024-02-15

Am I doing something wrong with the new API revisions or misunderstanding about its concepts and usages?

Please help!