Page unresponsive only on iOS

I have a screen with a list of clickable items that push a new page via the nav controller:

goToDetails(details) {
  this.navCtrl.push(DetailsPage, {
      "details": details,
      "type": this.type,
      "userId": this.getSelectedUserId()
    }, { animate: true, direction: 'left' });

This page has a nav bar at the top with a back button. When the back button is clicked, it goes back to the first screen and then the app becomes unresponsive for a few seconds. If you tap to go to the same or a different details page, the unresponsive state lasts longer. The more items in the list or the more times you go to a details page and back, the worse it gets.

There is no errors printed in the xcode console. I can see that the CPU usage increase with every tap when in the frozen state.

Ionic Info:

ionic (Ionic CLI) : 4.2.1 (/usr/local/lib/node_modules/ionic)
Ionic Framework : ionic-angular 3.3.0
@ionic/app-scripts : 1.3.7


cordova (Cordova CLI) : 7.0.1
Cordova Platforms : android 6.2.3, browser 4.1.0, ios 4.5.2
Cordova Plugins : no whitelisted plugins (17 plugins total)


Android SDK Tools : 26.1.1 (/app/Library/Android/sdk)
NodeJS : v8.6.0 (/usr/local/bin/node)
npm : 5.3.0
OS : macOS High Sierra
Xcode : Xcode 9.4.1 Build version 9F2000

I also have a popover on the details page that is much slower to respond then previous builds in the past. I believe this may be related as well.

This does not occur on the Android or Browser platforms.