Why my ion-list not getting the the data to display until i resize my window ionic 3

HI there
why my ion-list not getting the the data to display until i resize my window ionic 3.This is so strange.
I have used the splitpane in my project
I noticed this issue yesterday night and can’t make it till now.
I have array populated from database and which is used by ion-list with *ngFor . i console the array it seems to be having all data what i want but not showing in ion-list until resize it
Here is my ionic info

Ionic:

   ionic (Ionic CLI)  : 4.1.2 (/usr/local/lib/node_modules/ionic)
   Ionic Framework    : ionic-angular 3.9.2
   @ionic/app-scripts : 3.2.0

Cordova:

   cordova (Cordova CLI) : 8.0.0
   Cordova Platforms     : android 7.0.0, ios 4.5.5
   Cordova Plugins       : cordova-plugin-ionic-keyboard 2.1.2, cordova-plugin-ionic-webview 2.1.3, (and 5 other plugins)

System:

   ios-deploy : 1.9.2
   NodeJS     : v8.11.1 (/usr/local/bin/node)
   npm        : 5.6.0
   OS         : macOS High Sierra
   Xcode      : Xcode 9.4.1 Build version 9F2000

Here is my splitepane

<ion-split-pane>
<ion-menu [content]="content">
  <ion-header>
    <ion-toolbar>
      <ion-title>Legder</ion-title>
    </ion-toolbar>
  </ion-header>

  <ion-content>
    <ion-list>
      <button menuClose ion-item *ngFor="let p of pages" (click)="openPage(p)" start>
            <ion-icon name="{{p.icon}}"></ion-icon> {{p.title}}
          </button>
    </ion-list>
  </ion-content>

</ion-menu>

<ion-nav id="nav" [root]="rootPage" #content swipeBackEnabled="false" main></ion-nav>
</ion-split-pane>