Why won't my multer file uploads to AWS s3 work?

I was able to get my files to upload locally but am struggling to get it on AWS S3 Buckets. I'm receiving generic "cannot set headers after they are sent to the client" errors after submitting a request. All of the guides that I have found online are using the (soon to be deprecated) SDKv2 and I'm trying to use V3. I followed the multer-s3 documentation but I'm messing something up. I created a user on AWS with a custom policy that grants permission to write and read objects connected to my bucket as well.

controller:

const s3 = new S3Client({
  credentials: {
    accessKeyId: "myid",
    secretAccessKey: "mykey",
  },
  region: "us-east-2",
});
const s3Storage = multerS3({
  s3: s3,
  bucket: "mybucket",
  acl: "public-read",
  metadata: (req, file, cb) => {
    cb(null, { fieldname: file.fieldname });
  },
  key: (req, file, cb) => {
    cb(null, Date.now().toString());
  },
});
const upload = multer({
  storage: s3Storage,
});
exports.uploadFile = upload.single("file");
exports.createDocument = catchAsync(async (req, res, next) => {
  const newDoc = await Model.create({
    title: req.body.title,
    file: req.file.filename,
  });
  res.status(201).json({
    status: "success",
    data: { data: newDoc },
  });
});

router:

router.route("/").post(uploadFile, createDocument);