This is very simple to fix. You need to set the field 'Path to records in HTTP response body' to 'request_items'.
In the other post I mentioned you might need to do this, "You might actually need to use this field BTW. I am not sure what the response structures look like for Magento 2, but this is a pretty commonly used field for when the results are wrapped by a variable."
Here is the help text for the field too. "Use this field if the records returned by the API are not located at the root level of the HTTP response body. For example, an API could return records inside a container object like 'results.customers'."
