I am building an integration to a MIVA webstore and was baffled by why the API calls were not working from VBA-Web, but the identical call worked just fine from VSCode rest client.

After tracing the call in fiddler, I discovered the problem. For some reason the calls made through VBA-Web are changing the Content-Type header from application/json to application/json; Charset=UTF-8. The endpoint that I am calling is expecting exactly application/json, so it returns a failure base on the "wrong content type".

Why would it be appending the charset parameter, and how can I prevent it from doing so?