Credit Card validator - issue making function that checks if credit card arrays are valid

Question

https://pastebin.com/cxjqS1TZ

[Hello fellow engineers. I have been on the codecademy credit card challenge (code on pastebin link) and I have been unable to figure out why the findInvalidCard function does not work. I have tried everything up to the scope of what I have learned so far, which is all we are supposed to use for this challenge, and I fail to find the error. PS: sorry if I formatted this post incorrectly, I am brand new to programming and this is my first Stacks Overflow question. ]

Here is the link to the instructions

https://pastebin.com/EjW2S2BQ

[Thanks a lot, and please leave feedback as to how I can improve my question posts on the platform.]

"use strict";

// All valid credit card numbers
const valid1 = [4, 5, 3, 9, 6, 7, 7, 9, 0, 8, 0, 1, 6, 8, 0, 8];
const valid2 = [5, 5, 3, 5, 7, 6, 6, 7, 6, 8, 7, 5, 1, 4, 3, 9];
const valid3 = [3, 7, 1, 6, 1, 2, 0, 1, 9, 9, 8, 5, 2, 3, 6];
const valid4 = [6, 0, 1, 1, 1, 4, 4, 3, 4, 0, 6, 8, 2, 9, 0, 5];
const valid5 = [4, 5, 3, 9, 4, 0, 4, 9, 6, 7, 8, 6, 9, 6, 6, 6];

// All invalid credit card numbers
const invalid1 = [4, 5, 3, 2, 7, 7, 8, 7, 7, 1, 0, 9, 1, 7, 9, 5];
const invalid2 = [5, 7, 9, 5, 5, 9, 3, 3, 9, 2, 1, 3, 4, 6, 4, 3];
const invalid3 = [3, 7, 5, 7, 9, 6, 0, 8, 4, 4, 5, 9, 9, 1, 4];
const invalid4 = [6, 0, 1, 1, 1, 2, 7, 9, 6, 1, 7, 7, 7, 9, 3, 5];
const invalid5 = [5, 3, 8, 2, 0, 1, 9, 7, 7, 2, 8, 8, 3, 8, 5, 4];

// Can be either valid or invalid
const mystery1 = [3, 4, 4, 8, 0, 1, 9, 6, 8, 3, 0, 5, 4, 1, 4];
const mystery2 = [5, 4, 6, 6, 1, 0, 0, 8, 6, 1, 6, 2, 0, 2, 3, 9];
const mystery3 = [6, 0, 1, 1, 3, 7, 7, 0, 2, 0, 9, 6, 2, 6, 5, 6, 2, 0, 3];
const mystery4 = [4, 9, 2, 9, 8, 7, 7, 1, 6, 9, 2, 1, 7, 0, 9, 3];
const mystery5 = [4, 9, 1, 3, 5, 4, 0, 4, 6, 3, 0, 7, 2, 5, 2, 3];

// An array of all the arrays above
const batch = [
  valid1,
  valid2,
  valid3,
  valid4,
  valid5,
  invalid1,
  invalid2,
  invalid3,
  invalid4,
  invalid5,
  mystery1,
  mystery2,
  mystery3,
  mystery4,
  mystery5,
];

// Add your functions below:
// let [index, ...batchEle] = batch;
///Step 3
// console.log(batchEle);

let sumNewArr = 0;
const validateCred = (arr) => {
  let newArr = [];

  for (let i = arr.length - 1; i >= 0; i--) {
    if (i % 2 === 0) {
      arr[i] *= 2;
      if (arr[i] > 9) arr[i] -= 9;
      newArr.push(arr[i]);
    } else if (i % 2 === 1) {
      newArr.push(arr[i]);
    }
  }
  newArr.forEach((sum) => {
    sumNewArr += sum;
    //console.log(sumNewArr);
  });
  if (sumNewArr % 10 === 0) {
    return true;
  } else {
    return false;
  }
};

// console.log(validateCred(valid4));
let invalidCards = [];

const findInvalidCards = (badArr) => {
  for (let i = 0; i < badArr.length; i++) {
    if (validateCred(badArr[i]) === false) {
      invalidCards.push(badArr[i]);
    }
  }
  //   console.log(badArr);
  return invalidCards;
};

console.log(findInvalidCards(batch));
// console.log(validateCred(invalid1));

//valid 4
//mystery 3