White screen problem after splash screen

Ionic Framework
1

I have problem with app starting, shows 20 seconds white screen after splash screen,

Ionic:

Ionic CLI : 5.0.3 (C:\Users\ZEBRONIC\AppData\Roaming\npm\node_modules\ionic)
Ionic Framework : @ionic/angular 4.3.1
@angular-devkit/build-angular : 0.13.8
@angular-devkit/schematics : 7.3.8
@angular/cli : 7.3.8
@ionic/angular-toolkit : 1.5.1

Cordova:

Cordova CLI : 9.0.0 (cordova-lib@9.0.1)
Cordova Platforms : android 8.0.0, browser 6.0.0
Cordova Plugins : cordova-plugin-ionic-keyboard 2.1.3, cordova-plugin-ionic-webview 4.0.1, (and 20 other plugins)

Utility:

cordova-res : not installed
native-run : 0.2.6

System:

NodeJS : v10.15.3 (C:\Program Files\nodejs\node.exe)
npm : 6.4.1
OS : Windows 10

2

Did you check if there are errors in the log?

3

Yes, no any error in log. whole app work fire but only this issue in app opening.