Parse error Unexpected token '�' at 1:1 ��{ on flutter app when running firebase deploy

encounter the below message when trying to firebase deploy from root project

Error: Parse Error in ...\firestore.indexes.json Unexpected token '�' at 1:1 ��{

I have a flutter app, upon which I also have a functions folder. Below is the file position:

1. AppFolder
   • functions
     • .eslintrc.js
     • index.js
     • package.json
     • etc
   • lib
     • files relative to flutter app
   • test
     • test files relative to flutter app
   • web firestore.indexes.json
   • firebase.json
   • etc

I am running on windows 11 in a newly built pc (so maybe sth is missing?), other devs are running on mac, I have changed the EOF sequence to LF on the 3 files of the functions folder, I have also run these two commands inside the functions folder

npm install firebase-functions@latest firebase-admin@latest --save

npm install -g firebase-tools

npm version is 8.1.2

node version is v16.13.1

firestore.indexes.json is:

{
  "indexes": [
    {
      "collectionGroup": "something1",
      "queryScope": "COLLECTION",
      "fields": [
        {
          "fieldPath": "created",
          "order": "DESCENDING"
        },
        {
          "fieldPath": "something2",
          "order": "DESCENDING"
        }
      ]
    },
    {
      "collectionGroup": "something3",
      "queryScope": "COLLECTION",
      "fields": [
        {
          "fieldPath": "something4",
          "order": "ASCENDING"
        },
        {
          "fieldPath": "something5",
          "order": "DESCENDING"
        }
      ]
    }
  ],
  "fieldOverrides": []
}

.elslint.js is

module.exports = {
  "root": true,
  "env": {
    es6: true,
    node: true,
  },
  "extends": [
    "eslint:recommended",
    "google",
  ],
  "rules": {
    quotes: ["error", "double"],
  },
  "parserOptions": {
    "ecmaVersion": 2020,
  },
};

and package.json is

  "name": "functions",
  "description": "Cloud Functions for Firebase",
  "scripts": {
    "lint": "eslint .",
    "serve": "firebase emulators:start --only functions",
    "shell": "firebase functions:shell",
    "start": "npm run shell",
    "deploy": "firebase deploy --only functions",
    "logs": "firebase functions:log"
  },
  "engines": {
    "node": "14"
  },
  "main": "index.js",
  "dependencies": {
    "axios": "^0.24.0",
    "device-detector-js": "^3.0.0",
    "firebase": "^9.2.0",
    "firebase-admin": "^10.0.1",
    "firebase-functions": "^3.16.0"
  },
  "devDependencies": {
    "eslint": "^8.1.0",
    "eslint-config-google": "^0.14.0",
    "firebase-functions-test": "^0.3.3"
  },
  "private": true
}

Please keep in mind that in an older pc running windows 10 and I can deploy by changing only to the LF and running the above commands.