Inventory_levels/set returns 404 NotFound

[RobVdH]

When using inventory_levels/set.json in production environment I always get StatusCode 404, NotFound.
The same code is working in DEV and TEST.

The request is:
https://<store>.myshopify.com/admin/api/2021-07/inventory_levels/set.json
The body contains:
- inventory_item_id = 43085608222870
- location_id = 65014169750
- available = 0
- disconnect_if_necessary = false

RequestId = 14b81e55-b79c-48d9-9791-2c8789a9ce6f

I can make the same request in Postman which succeeds.

Inventory item and location id's do exist, this is the response from 'inventory_levels.json':

{

    "inventory_levels": [

        {

            "inventory_item_id": 43085608222870,

            "location_id": 65014169750,

            "available": 3,

            "updated_at": "2021-10-27T14:48:05+02:00",

            "admin_graphql_api_id": "gid://shopify/InventoryLevel/99350085782?inventory_item_id=43085608222870"

        }

    ]

}

What am I doing wrong?

Kind regards, Rob