evaporate.js not sending to_sign from mobile device

I am working on an app that has web and mobile ui components. We are using evaporate.js to call an endpoint that will return a pre-signed url for chunk uploading to aws buckets. This concept works when used from react and it sends the to_sign querystring parameter to create the pre-signed url. For some reason, when this code is run from react native the to_sign query string value is not getting passed to the endpoint. What could possibly block the to_sign parameter from getting passed from evaporate, this same code is working for react app? Here is the code we are calling from react native:

const uploader = Evaporate.create({
    signerUrl: config.SIGNER_URL,
    aws_key: config.AWS_KEY,
    bucket: config.BUCKET,
    awsRegion: config.AWS_REGION,
    cloudfront: true,
    xhrWithCredentials: true,
    computeContentMd5: true,
    cryptoMd5Method: (d) => btoa(sparkMD5.ArrayBuffer.hash(d, true)),
    cryptoHexEncodedHash256: sha256,
  });

  const uploadFile = (file, cb) => {
    setLoading(true);
    setUploadingError("");
    let newName = uuidv4();
    let extension = file.name.split(".");

    uploader
      .then((evaporate) => {
        evaporate
          .add({
            file,
            name: newName + "." + extension[2],
          })
          .then((res, err) => {
            if (res) {
              cb(res);
              setLoading(false);
            } else if (err) {
              setUploadingError("Something went wrong");
              setLoading(false);
            }
          });
      })
      .catch((err) => {
        setUploadingError("Something went wrong");
        setLoading(false);
      });
  };

Not sure if this is a reach, but the mobile version does not supply a url for CORS as opposed to the url set on the CORS s3 admin screen, so could this possibly be a CORS issue?