After ng build --prod, why am I getting errors in main.js:1 and polyfills.js:1, rather than in components that I created, How to undo this?

Question

I wanted to deploy an almost finished Angular project and for deployment I executed ng build --prod. It created a dist which than I deployed to the server. All understood and Ok till here but now when I change stuff in the project and execute 'ng serve -o' I don't see console messages that I set in those components where I wrote those console.log messages but rather these are being referred from 'main.js:1' and 'polyfills.js:1'.

I am still getting those console messages but I don't know in which component it is being printed on the console.

ERROR TypeError: Cannot read property 'UserzAccessStatus' of undefined
    at main.js:1
    at i.<computed> (polyfills.js:1)
    at e.invokeTask (polyfills.js:1)
    at Object.onInvokeTask (main.js:1)
    at e.invokeTask (polyfills.js:1)
    at t.runTask (polyfills.js:1)
    at t.invokeTask (polyfills.js:1)
    at invoke (polyfills.js:1)
    at r.args.<computed> (polyfills.js:1)

Console.log() messages in chrome's console

package.json file

{
  "name": "gbcl",
  "version": "0.0.0",
  "scripts": {
    "ng": "ng",
    "start": "ng serve",
    "build": "ng build",
    "test": "ng test",
    "lint": "ng lint",
    "e2e": "ng e2e",
    "start:server": "nodemon server.js"
  },
  "private": true,
  "dependencies": {
    "@angular/animations": "~12.0.0",
    "@angular/common": "~12.0.0",
    "@angular/compiler": "~12.0.0",
    "@angular/core": "~12.0.0",
    "@angular/forms": "~12.0.0",
    "@angular/platform-browser": "~12.0.0",
    "@angular/platform-browser-dynamic": "~12.0.0",
    "@angular/router": "~12.0.0",
    "bcrypt": "^5.0.1",
    "body-parser": "^1.19.0",
    "bootstrap": "^4.5.2",
    "express": "^4.17.1",
    "jquery": "^3.6.0",
    "mongoose": "^5.12.8",
    "mongoose-unique-validator": "^2.0.3",
    "popper.js": "^1.16.1",
    "rxjs": "~6.5.3",
    "tslib": "^2.2.0",
    "zone.js": "~0.11.4"
  },
  "devDependencies": {
    "@angular-devkit/build-angular": "~12.0.0",
    "@angular/cli": "^12.0.0",
    "@angular/compiler-cli": "^12.0.0",
    "@types/jasmine": "~3.7.2",
    "@types/jasminewd2": "~2.0.9",
    "@types/node": "^15.0.3",
    "codelyzer": "^6.0.2",
    "jasmine-core": "~3.7.1",
    "jasmine-spec-reporter": "~7.0.0",
    "karma": "~6.3.2",
    "karma-chrome-launcher": "~3.1.0",
    "karma-coverage-istanbul-reporter": "~3.0.3",
    "karma-jasmine": "~4.0.1",
    "karma-jasmine-html-reporter": "^1.6.0",
    "nodemon": "^2.0.7",
    "protractor": "~7.0.0",
    "ts-node": "~9.1.1",
    "tslint": "~6.1.0",
    "typescript": "~4.2.4"
  }
}

tsconfig.app.json file

{
  "extends": "./tsconfig.base.json",
  "compilerOptions": {
    "outDir": "./out-tsc/app",
    "types": []
  },
  "angularCompilerOptions":{
    "enableIvy": true,
    "strictTemplates": true,
    "strictInjectionParameters": true
  },
  "files": [
    "src/main.ts",
    "src/polyfills.ts"
  ],
  "include": [
    "src/**/*.d.ts"
  ]
}

If further information about any file is required than please ask.

Answer 1

To see the exact location of the error in production environment

ng build --prod --build-optimizer --sourceMap=true you can get build.

Your error is most likely "???????" There is no "UserzAccessStatus" key in the object you print with its name.

Answer 2

You have to update the serve configuration part in your angular.json according to this reply

Angular 12 'ng serve' builds apps slowly, almost like production builds