File Upload Error:400 on API Post request

Question

I have an API Post method, that gets IFormFile as input, and uploads the file to cloud storage. This code is working fine with localhost, but when the same Post action throws a 400 error in production-hosted environment (core containerized image host to Kubernetes cluster).

Here is my Action Method,

[HttpPost("")]
[Consumes("multipart/form-data")]
public async Task<ActionResult> UploadFileAttachmentAsync(IFormFile file)
{
    var result = await this.attachmentService.UploadAttachmentAsync(file);

    if (result != null)
    {
        return this.StatusCode(StatusCodes.Status200OK);
    }

    return this.StatusCode(StatusCodes.Status500InternalServerError);
}

When I call this API post action from localhost development environment in Swagger UI, postman, or anywhere, it works fine, that I can get the file input to this action. https://localhost:4242/attachments

However, the Same action call is not working when I use the hosted API, https://test-api.example.com/attachments,

Swagger Input be like, Postman input,

Receiving the 400 bad request error,

{
  "type": "https://tools.ietf.org/html/rfc7231#section-6.5.1",
  "title": "Bad Request",
  "status": 400,
  "traceId": "00-7f70c739657ae91cccffdb47400cdf2f-0f3bd7b4bcce3774-00"
}

Iformfile input validation itself failed here, Could you please what I have done wrong in the hosted environment?