Unable to get _signTypedData to provide USDC POS on Polygon with right values

[rajasmasala]

Hi, first of all thank you for this wonderful set of packages. I really do enjoy using them and they really make life easer when coding.

However, I do have a major issue that has going on for more than a week now where I just can't get the signTypedData function to work with the Permit function of USDC (POS) on Polygon (Error thrown is 'Permit: invalid signature'). I would really like help to get past this. The permit type is:
// = keccak256("Permit(address owner,address spender,uint256 value,uint256 nonce,uint256 deadline)")
from the Polygonscan verified contract.

My code is as follows (I have left in a working sushi swap to indicate it is meant to be run on Polygon mainnet fork ):

`
const { ethers, run, network } = require("hardhat");
require('dotenv').config({path:__dirname+'../.env'});
const url = "http://localhost:8545";
const provider = new ethers.providers.JsonRpcProvider(url);
const USDC = "0x2791Bca1f2de4661ED88A30C99A7a9449Aa84174";
const USDCDecs = 6;
const usdcAbi = require('./usdc.json');
const SushiAddress = "0x1b02dA8Cb0d097eB8D57A175b88c7D8b47997506";
const SUSHIABI = require('./sushirouter.json');

async function main() {

    console.log("starting...");
    const Sender = await provider.getSigner(process.env.Account2);
    const Recipient = await provider.getSigner(process.env.Account3);
    const sender = Sender._address;
    const recipient = Recipient._address;

    tokenContract = await ethers.getContractAt(usdcAbi,
        USDC,
        Sender);
    
    console.log("Line 27...");

    const amount = 1e6;
    deadline = Date.now()+3600;
    const chainId = 137;
    //update nonce from USDC contract:
    nonce = await tokenContract.nonces(Sender._address);
    console.log("Nonce received is", nonce);
    nonce = ethers.BigNumber.from(nonce).add(1);
    console.log("Nonce incremented is", nonce);
    console.log("Line 33...");
    tokenName = await tokenContract.name();
    tokenVersion = await tokenContract.EIP712_VERSION();
    console.log("Line 35..");
    console.log("nonce, ", nonce, "tokenNamem, ", 
                tokenName, "tokenVersion, ", tokenVersion); 

    const domain = {name: tokenName,
            version: tokenVersion,
            chainId: chainId,
            verifyingContract: USDC};

        const types = {
            Permit:[
            {name:"owner",type:"address"},
            {name:"spender",type:"address"},
            {name:"value",type:"uint256"},
            {name:"nonce", type:"uint256"},
            {name:"deadline", type:"uint256"}
        ]};
        console.log("line 82..");

        const value = {
            owner: sender, //variable to define
            spender: recipient,  //variable to define
            value: amount, //variable to define
            nonce: nonce,
            deadline: deadline
        };

    
    signature = await Sender._signTypedData(domain, types, value);

    const {v, r, s} = ethers.utils.splitSignature(signature);


    console.log("Signed info... I think!");

    const verifiedAddress = await ethers.utils.verifyTypedData(
        domain,
        types,
        value,
        signature,
      );

      console.log(ethers.utils._TypedDataEncoder.getPayload(domain, types, value));

      console.log("signature:", signature);
      console.log("signature length:", signature.length);
      console.log("trying for v, r, s:", v, r, s);
      console.log ("ethersjs verified address is:", verifiedAddress);
      console.log("expected address is:", Sender._address);
     //Above works as expeccted

      //Swap funds to USDC.
      sushiswap = await ethers.getContractAt(SUSHIABI,
        SushiAddress,
        Sender);
        console.log("started...");
      sushiswap = await sushiswap.connect(Sender);
      sushiWeth = String(await sushiswap.WETH());
      console.log("weth gotten...");

      await sushiswap.swapExactETHForTokens(
        0,
        [sushiWeth, USDC],
        Sender._address,
        Date.now()+300,
        {value:ethers.utils.parseEther("10")}
    );

    var tokenBalance = await tokenContract.balanceOf(Sender._address);
    console.log("USDC token balance after swap is: ", 
                ethers.utils.formatUnits(tokenBalance, USDCDecs));
    
    await tokenContract.permit(
        sender,
        recipient,
        amount,
        deadline,
        v,
        r,
        s
    );
    console.log("line 147...");

    var tokenBalance = await tokenContract.balanceOf(Sender._address);
    console.log("USDC token balance after transfer is: ", 
                ethers.utils.formatUnits(tokenBalance, USDCDecs));
}

main()
  .then(() => process.exit(0))
  .catch((error) => {
    console.error(error);
    process.exit(1);
  });`

Any help would be deeply appreciated!
Kind regards,
rajasmasala

P.s. One more detail if it can help: this is the payload from the above typed data signature object that gets console logged from _TypedDataEncoder:

{
  types: {
    Permit: [ [Object], [Object], [Object], [Object], [Object] ],
    EIP712Domain: [ [Object], [Object], [Object], [Object] ]
  },
  domain: {
    name: 'USD Coin (PoS)',
    version: '1',
    chainId: '137',
    verifyingContract: '0x2791bca1f2de4661ed88a30c99a7a9449aa84174'
  },
  primaryType: 'Permit',
  message: {
    owner: '0xf39fd6e51aad88f6f4ce6ab8827279cfffb92266',
    spender: '0x70997970c51812dc3a010c7d01b50e0d17dc79c8',
    value: '1000000',
    nonce: '5',
    deadline: '1649584414019'
  }
}`
```

[nyp0x]

Have you found a solution for this? It seems the problem is with USDC specifically. I cannot reproduce the issue with a newly deployed permittable ERC20.

[nyp0x]

I got it working: https://gist.github.com/nyp0x/fca5a05210818651073828de084f6aa4