Module not found when building flutter app for IOS

Question

So I'm having a problem when building my Flutter app in release mode for flutter.

When I build my Flutter app in debug mode it works fine and I can use my app in any emulator without any problem. But when I click edit scheme and try to run it in release mode the build fails and I get cloud_firestore module not found.

The reason I'm trying to build for release mode is that when I submitted my app for the app store it got rejected almost immediately and the reason was that the app crashed when launching.

Information you should know: Mac Version:

App works fine in debug mode

XCode version: v14.2

Flutter doctor: No errors

Cocoapods version: 1.15.2

Flutter version: 3.19.5 (Stable version)

Dart version: 3.3.3

Podfile content:

platform :ios, '12.0'

ENV['COCOAPODS_DISABLE_STATS'] = 'true'


project 'Runner', {
  'Debug' => :debug,
  'Profile' => :release,
  'Release' => :release,
}

def flutter_root
  generated_xcode_build_settings_path = File.expand_path(File.join('..', 'Flutter', 'Generated.xcconfig'), __FILE__)
  unless File.exist?(generated_xcode_build_settings_path)
    raise "#{generated_xcode_build_settings_path} must exist. If you're running pod install manually, make sure flutter pub get is executed first"
  end

  File.foreach(generated_xcode_build_settings_path) do |line|
    matches = line.match(/FLUTTER_ROOT\=(.*)/)
    return matches[1].strip if matches
  end
  raise "FLUTTER_ROOT not found in #{generated_xcode_build_settings_path}. Try deleting Generated.xcconfig, then run flutter pub get"
end

require File.expand_path(File.join('packages', 'flutter_tools', 'bin', 'podhelper'), flutter_root)

flutter_ios_podfile_setup

target 'Runner' do
  use_frameworks!
  use_modular_headers!

  flutter_install_all_ios_pods File.dirname(File.realpath(__FILE__))
  target 'RunnerTests' do
    inherit! :search_paths
  end
end

post_install do |installer|
  installer.pods_project.targets.each do |target|
    flutter_additional_ios_build_settings(target)
  end
end

Pubspec.yaml content:

name: lifenavigator
version: 1.0.0+1
publish_to: none
description: A new Flutter project.
environment: 
  sdk: '>=3.2.3 <4.0.0'

dependencies: 
  cupertino_icons: ^1.0.2
  get: 4.6.6
  flutter: 
    sdk: flutter
  google_fonts: 6.1.0
  firebase_core: ^2.27.0
  firebase_auth: ^4.17.8
  font_awesome_flutter: ^10.7.0
  convex_bottom_bar: ^3.2.0
  cloud_firestore: ^4.15.8
  firebase_messaging: ^14.7.19
  google_sign_in: ^6.2.1
  flutter_facebook_auth: ^6.1.1
  flutter_dotenv: ^5.1.0
  dio: ^5.4.1
  url_launcher: ^6.2.5
  flutter_launcher_icons: ^0.13.1
  google_mobile_ads: ^5.0.0

dev_dependencies: 
  flutter_lints: ^3.0.2
  flutter_test: 
    sdk: flutter
  flutter_launcher_icons: "^0.13.1"


flutter_launcher_icons:
  android: "launcher_icon"
  ios: true
  image_path: "assets/applogo.png"
flutter: 
  uses-material-design: true
  assets:
    - assets/
    - .env

Solutions I tried: I tried cleaning the previous builds and building again.

I tried Flutter upgrade and pod repo update and flutter pub get and pod install

I tried adding cloudFirestore in Podfile as pod 'FirebaseCore', :modular_headers => true (trigggered a new error)

I was trying to build my application for release mode but the build failed and I got module "cloud_firestore" not found