ionic startup too slow

Hello ı have a big problem

I have no problem with the speed after the application is opened, just the start is very slow

I approached the end of the app and tried it on two different phones(both are HUAWEI). When i tried on the first phone ı waited on the blank screen for between 8-12 seconds after splashscreen. When i tried on the second phone after splashscreen the application does not open and always stays on a blank screen.

what is the problem ? thanks in advance

I tried several times for build

ionic build --prod , ionic build --prod --release

ionic capacitor sync

ionic capacitor run android

ionic info :

Ionic:

   Ionic CLI                     : 6.11.0 (C:\Users\Zafer\AppData\Roaming\npm\node_modules\@ionic\cli)
   Ionic Framework               : @ionic/angular 5.3.3
   @angular-devkit/build-angular : 0.1000.8
   @angular-devkit/schematics    : 10.0.8
   @angular/cli                  : 10.0.8
   @ionic/angular-toolkit        : 2.3.3

Capacitor:

   Capacitor CLI   : 2.4.1
   @capacitor/core : 2.4.1

Utility:

   cordova-res : not installed
   native-run  : not installed

System:

   NodeJS : v10.16.3 (C:\Program Files\nodejs\node.exe)
   npm    : 6.9.0
   OS     : Windows 10