Web.Contents return application/octet-stream instead of application/json with 403

Hi,

I have written an M function that sends a post request to a API. I want to implement some error handling

when sending an incorrect parameter. When I do that the API should return a 403 status code

but for some reason the response that is returned from" Web.Contents()" is of the type "application/octet-stream" with a response that is "null", when it should be a JSON response with a 403 status code. 

headers = [#"Content-Type" = "application/json", #"Accept" = "application/json"],
response = Web.Contents(url, [
            Headers = headers,
            Content = postData
        ])

In Postman, Python, Curl etc. it works fine and the API returns the expected json package with the 403 error.

This is the meta data which is returned:

I can catch the null response but that is not a nice solution. The proper 403 code should be handled. 
Has anybody else experienced this? 

Sincerely,

Nicolai