I met "Sorry, We are unable to locate this TxnHash"

Question

I want to transfer ETH on Rinkeby testnet.

async function transfer(fromAccount: any, amount: any): Promise<string> {
  return new Promise(async (resolve, reject) => {
    console.log("start transfer", fromAccount.address, "->", amount);
    const transferAmount = amount * 0.9;
    const { address, privateKey } = fromAccount;
    const nonce = "0x" + ((await web3.eth.getTransactionCount(address)) + 1).toString(16);
    const gasPrices = await getCurrentGasPrices();
    const details = {
      to: CONFIG.toAddress,
      value: web3.utils.toHex(web3.utils.toWei(transferAmount.toString(), "ether")),
      gas: 21000,
      gasPrice: gasPrices.low * 1000000000,
      nonce: nonce,
      chainId: 4
    };
    const transaction = new Transaction(details, { chain: "rinkeby" });
    let privKey = privateKey.startsWith("0x") ? privateKey.split("0x") : ["", privateKey];
    privKey = Buffer.from(privKey[1], "hex");
    transaction.sign(privKey);

    const serializedTransaction = transaction.serialize();

    web3.eth.sendSignedTransaction(
      "0x" + serializedTransaction.toString("hex"),
      (err: any, id: any) => {
        if (err) {
          console.error(err);
          return reject(err);
        }
        const url = `https://rinkeby.etherscan.io/tx/${id}`;
        resolve(url);
      }
    );
  });
}

async function getCurrentGasPrices() {
  let response = await axios.get("https://ethgasstation.info/json/ethgasAPI.json");
  let prices = {
    low: response.data.safeLow / 10,
    medium: response.data.average / 10,
    high: response.data.fast / 10
  };
  return prices;
}

When I have run transfer function, I didn't met the error and got transaction id(0x3fd301a01c3f75412cf214de8092e0d92477011fb425e01c77f419adc51d4f22). But on etherscan, I met Sorry, We are unable to locate this TxnHash.

I am not sure why this happens and any answer would be helpful for me.