Slow performance and slow switching tabs on ios device ionic v4.10.1

Hi everyone, I’m using firebase as a backend (real-time database).
the slow performance happens when I log in at the first time on the app the app is so so slow on ios device and it’s fast on android devices.
The app performance only becomes greater after :

  • Creating a new account
  • Close the app and perform autologin

I’ve tried everything
I tried to build the ios app with --prod – release
I tried to comment all the loading functions from the main page after the login
I tried to remove the platform several times and add different ios versions
I tried to remove lots of plugins that are not used anymore
I tried to install the WekWebview

the weird thing is the previous version of the application is working fine and its performance is greater than this one so I tried to run the previous version on my iPhone 7 plus and still it’s slow, do I have to downgrade my Cordova or ionic version or even node version?

It has been 3 continuous days continuous 7 hours each day.
Anyone experiencing the same problem? anyone know how to fix this?


   ionic (Ionic CLI)  : 4.10.1 (/usr/local/lib/node_modules/ionic)
   Ionic Framework    : ionic-angular 3.9.2
   @ionic/app-scripts : 3.2.1


   cordova (Cordova CLI) : 7.1.0
   Cordova Platforms     : ios
   Cordova Plugins       : cordova-plugin-ionic-keyboard 2.1.3, cordova-plugin-ionic-webview 1.2.1, (and 17 other plugins)


   Android SDK Tools : 25.2.3 (/Users/khaledAlhindi/Library/Android/sdk)
   ios-deploy        : 1.9.4
   NodeJS            : v10.15.1 (/usr/local/bin/node)
   npm               : 5.3.0
   OS                : macOS Mojave
   Xcode             : Xcode 10.1 Build version 10B61

com.synconset.imagepicker 2.1.10 "ImagePicker"
cordova-plugin-add-swift-support 1.6.0 "AddSwiftSupport"
cordova-plugin-camera 3.0.0 "Camera"
cordova-plugin-device 2.0.2 "Device"
cordova-plugin-dialogs 2.0.1 "Notification"
cordova-plugin-enable-multidex 0.1.3 "Enable Multidex"
cordova-plugin-fcm-with-dependecy-updated 2.4.0 "Cordova FCM Push Plugin"
cordova-plugin-file 5.0.0 "File"
cordova-plugin-file-transfer 1.7.1 "File Transfer"
cordova-plugin-filepath 1.0.2 "FilePath"
cordova-plugin-ionic-keyboard 2.1.3 "cordova-plugin-ionic-keyboard"
cordova-plugin-ionic-webview 1.2.1 "cordova-plugin-ionic-webview"
cordova-plugin-keyboard 1.2.0 "Keyboard"
cordova-plugin-photo-library 2.1.1 "Photo Library"
cordova-plugin-splashscreen 4.0.3 "Splashscreen"
cordova-plugin-statusbar 2.3.0 "StatusBar"
cordova-plugin-whitelist 1.3.1 "Whitelist"
cordova-sqlite-storage 2.2.0 "Cordova sqlite storage plugin"
cordova-support-android-plugin 1.0.1 "cordova-support-android-plugin"
cordova-support-google-services 1.2.1 "cordova-support-google-services"