Cannot set headers after they are sent to the client when I try to make an update request

I am trying to create a CRUD. I have the UPDATE created, but when I try to request from postman, I get the following error:

Error [ERR_HTTP_HEADERS_SENT]: Cannot set headers after they are sent to the client at ServerResponse.setHeader (_http_outgoing.js:526:11) at ServerResponse.header (E:\freebooks-core-api\node_modules\express\lib\response.js:771:10) at ServerResponse.send (E:\freebooks-core-api\node_modules\express\lib\response.js:170:12) at ServerResponse.json (E:\freebooks-core-api\node_modules\express\lib\response.js:267:15) at ServerResponse.send (E:\freebooks-core-api\node_modules\express\lib\response.js:158:21) at Object.exports.success (E:\freebooks-core-api\network\response.js:3:6) at E:\freebooks-core-api\components\book\network.js:32:18 at processTicksAndRejections (internal/process/task_queues.js:97:5) { code: 'ERR_HTTP_HEADERS_SENT' } (node:2844) UnhandledPromiseRejectionWarning: Error [ERR_HTTP_HEADERS_SENT]: Cannot set headers after they are sent to the client at ServerResponse.setHeader (_http_outgoing.js:526:11) at ServerResponse.header (E:\freebooks-core-api\node_modules\express\lib\response.js:771:10) at ServerResponse.send (E:\freebooks-core-api\node_modules\express\lib\response.js:170:12) at ServerResponse.json (E:\freebooks-core-api\node_modules\express\lib\response.js:267:15) at ServerResponse.send (E:\freebooks-core-api\node_modules\express\lib\response.js:158:21) at Object.exports.error (E:\freebooks-core-api\network\response.js:12:6) at E:\freebooks-core-api\components\book\network.js:34:16 at processTicksAndRejections (internal/process/task_queues.js:97:5) (node:2844) UnhandledPromiseRejectionWarning: Unhandled promise rejection. This error originated either by throwing inside of an async function without a catch block, or by rejecting a promise which was not handled with .catch(). To terminate the node process on unhandled promise rejection, use the CLI flag --unhandled-rejections=strict (see https://nodejs.org/api/cli.html#cli_unhandled_rejections_mode). (rejection id: 1) (node:2844) [DEP0018] DeprecationWarning: Unhandled promise rejections are deprecated. In the future, promise rejections that are not handled will terminate the Node.js process with a non-zero exit code.

As I read in the error, this comes from the following files:

response.js in my network folder

exports.success = function (req, res, data, status) {
  res.status(status || 200)
    .send({
      error: '',
      data
    })
}

exports.error = function (req, res, error, status, log) {
  console.log(log)
  res.status(status || 500)
    .send({
      error,
      data: ''
    })
}

and network.js in my book (component) folder:

const router = require('express').Router()
const response = require('../../network/response')
const controller = require('./controller')

router.get('/', function (req, res) {
    controller.getBooks()
        .then( data => {
            response.success(req, res, data, 200)
        })
        .catch( err => {
            response.error(req, res, 'Unexpected Error', 500, err)
        })
})

router.post('/', function (req, res) {
  const book = req.body
  console.log(book)
  controller.addBook(book).then( data => {
    response.success(req, res, book, 201)
  })
    .catch(err => {
      response.error(req, res, 'Internal error', 500, err)
    })
})

router.patch('/:id', function(req, res) {
  const { id } = req.params
  console.log(id)
  const book = req.body
  controller.updateBook(id, book)
    .then( data => {
        response.success(req, res, data, 200)
    }).catch( err => {
      response.error(req, res, 'Internal error', 500, err)
    }) 
  res.send('Ok')
})

module.exports = router

but since I am calling the controller and the error is running on that line, this is the code:

const store = require('./store')

function getBooks () {
  return new Promise((resolve, reject) => {

    resolve(store.list())
  })
}

function addBook (book) {
  return new Promise((resolve, reject) => {
    if (!book) {
      reject('I reject')
      return false
    } else {

      resolve(book)
      store.add(book)
    }
  })
}

 function updateBook (id, book) {
  return new Promise( async (resolve, reject) => {
      if (!id || !book) {
          reject('Invalid data')
          return false
      } else {
        const result = await store.update(id, book)
        resolve(result)
      }

  })
}

function deleteBook (id) {
  return new Promise( async (resolve, reject) => {
      if (!id) {
          reject('Invalid data')
          return false
      } else {
        const result = await store.update(id)
        resolve(result)
      }

  })
}

module.exports = {
  addBook,
  getBooks,
  updateBook,
  deleteBook
}

finally the store

const db = require('mongoose')
const Model = require('./model')

db.Promise = global.Promise
db.connect(`mongodb+srv://fewtwtwfwe:efwefwecwecw@ferwrtervsefwg/test?retryWrites=true&w=majority`, {
    useNewUrlParser: true,
    useUnifiedTopology: true
}).then( () => {
    console.log(`Database connected`)
}).catch( err => {
    console.error(err)
})

function addBook(book) {
    const myBook = new Model(book)
    myBook.save()
}

async function getBooks() {
   const books =  await Model.find()
   return books
}

async function updateBook(id, book) {
    const foundBook = await Model.findOne({
        '_id':id
    })
    foundBook.book = book
    const newBook = await foundBook.save()
    return newBook
}

async function deleteBook(id) {
    const foundBook = await Model.findOne({
        '_id':id
    })
}


module.exports = {
    add: addBook,
    list: getBooks,
    update: updateBook,
    delete: deleteBook,
}

I modified the data of the connection to the database, because I am sure that the error does not lie there, I have made other requests and apparently everything is fine. Any idea?