[Ethereum] TypeError: _getWeb3__WEBPACK_IMPORTED_MODULE_0__.default.eth is undefined

I'm not familiar with webpack, but after reading this error all I know that I import one module that is undefined by webpack. However, I don't know why export default new web3.eth.Contract(abi, address); this row can cause this problem. Since I already export web3 from my file getWeb3.js and then import it to this error file storehash.js. I can't find any error in my getWeb3.js file since it is created by truffle unbox react and then all I changed in this file is to change the network to rinkby network. Can anybody help me?

storehash.js

import web3 from './getWeb3';

//access our local copy to contract deployed on rinkeby testnet
//use your own contract address
const address = '0xD0e9A858b68cA1981aa524D22B244C3C3A237ad4';//'0x8f388d3a1a4d011eECb3822EE6bDf78902d0F6f1'; 
//use the ABI from your contract
const abi = [
    {
      "constant": false,
      "inputs": [
        {
          "name": "x",
          "type": "string"
        }
      ],
      "name": "sendHash",
      "outputs": [],
      "payable": false,
      "stateMutability": "nonpayable",
      "type": "function"
    },
    {
      "constant": true,
      "inputs": [],
      "name": "getHash",
      "outputs": [
        {
          "name": "x",
          "type": "string"
        }
      ],
      "payable": false,
      "stateMutability": "view",
      "type": "function"
    }
]

export default new web3.eth.Contract(abi, address);

getweb3.js

import Web3 from "web3";

const getWeb3 = () =>
  new Promise((resolve, reject) => {
    // Wait for loading completion to avoid race conditions with web3 injection timing.
    window.addEventListener("load", async () => {
      // Modern dapp browsers...
      if (window.ethereum) {
        const web3 = new Web3(window.ethereum);
        try {
          // Request account access if needed
          await window.ethereum.enable();
          // Acccounts now exposed
          resolve(web3);
        } catch (error) {
          reject(error);
        }
      }
      // Legacy dapp browsers...
      else if (window.web3) {
        // Use Mist/MetaMask's provider.
        const web3 = window.web3;
        console.log("Injected web3 detected.");
        resolve(web3);
      }
      // Fallback to localhost; use dev console port by default...
      else {
        const provider = new Web3.providers.HttpProvider(
          'https://rinkeby.infura.io/v3/172a5e1258804b4d919ded68b1ae1490'
        );
        const web3 = new Web3(provider);
        console.log("No web3 instance injected, using Local web3.");
        resolve(web3);
      }
    });
  });

export default getWeb3;

Below is the error that I got in my browser console.