Scroll delay on iPad

I'm seeing a delay of around half a second when starting a scroll on an iPad. When trying the same scroll gesture on iPhone and Android, the scroll starts immediately and is very smooth.

<ion-header>
    ...
</ion-header>
<ion-content class="has-header">
  <div class="blah-picker">
    <div class="results">
      <ion-grid>
        <ion-row>
          <ion-col col-12 col-md-6 *ngFor="let blahItem of blahList">

            <div>
              <ion-item class="item item-block item-ios" tappable (click)="selected(blahItem)">
               ...
              </ion-item>
            </div>

          </ion-col>
        </ion-row>
      </ion-grid>
   </div>
  </div>
</ion-content>

I'm using Ionic 3.4.0 and Cordova 7.0.1:

$ ionic info

global packages:

    @ionic/cli-utils : 1.4.0
    Cordova CLI      : 7.0.1
    Ionic CLI        : 3.4.0

local packages:

    @ionic/app-scripts              : 1.3.7
    @ionic/cli-plugin-cordova       : 1.4.0
    @ionic/cli-plugin-ionic-angular : 1.3.1
    Cordova Platforms               : android 6.2.3 ios 4.4.0
    Ionic Framework                 : ionic-angular 3.4.0

System:

    Node       : v6.10.0
    OS         : OS X El Capitan
    Xcode      : Xcode 8.2.1 Build version 8C1002
    ios-deploy : 1.9.1
    ios-sim    : 5.0.13
    npm        : 3.10.10