iOS page transitions show old page under the new page for a short period

Ionic Framework
1

A very short and simple question…

Just started testing my Ionic app on iOS after upgrading to Ionic 4, and I have notices, when I transition to a page, eg using navigateForward, I still seem to see the old page under it for just around 1 second, so for a very short while, graphics looks mixed up.

Have the following evn…

onic:

   Ionic CLI                     : 5.2.3 (/usr/local/lib/node_modules/ionic)
   Ionic Framework               : @ionic/angular 4.6.2
   @angular-devkit/build-angular : 0.13.8
   @angular-devkit/schematics    : 7.2.4
   @angular/cli                  : 7.3.8
   @ionic/angular-toolkit        : 1.4.1

Cordova:

   Cordova CLI       : 9.0.0 (cordova-lib@9.0.1)
   Cordova Platforms : ios 5.0.1
   Cordova Plugins   : cordova-plugin-ionic-keyboard 2.1.3, cordova-plugin-ionic-webview 4.1.1, (and 12 other plugins)

Utility:

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

System:

   Android SDK Tools : 26.1.1 (/Users/Development/.android-sdk-macosx/)
   ios-deploy        : 1.9.4
   ios-sim           : 8.0.1
   NodeJS            : v10.15.3 (/usr/local/bin/node)
   npm               : 6.4.1
   OS                : macOS High Sierra
   Xcode             : Xcode 9.4.1 Build version 9F2000

Has anyone else noticed this, or perhaps know a way around it?

Thanks in advance