bug: transitions are slower on iOS 14 beta

Bug Report

Ionic version:

[ ] 4.x [x] 5.x

Current behavior:

Page and side menu transitions are slower in iOS 14 than on iOS 13.

Issue seems similar to an iOS 13 bug and I opened a bug for Webkit: https://bugs.webkit.org/show_bug.cgi?id=213504

Expected behavior:

iOS 14 should have fast transitions too. This bug is to track this on the Ionic side if this is a Webkit bug or not.

Steps to reproduce:

Go to the repro app and open pages: https://ios-repro.web.app/list

Related code:

Repro app: https://github.com/NiklasMerz/repro-stutter

Other information: Probably Webkit bug: https://bugs.webkit.org/show_bug.cgi?id=213504

Only on iOS 14 beta now.

Ionic info:

Ionic:

   Ionic CLI                     : 6.10.1 (/Users/niklasmerz/.nvm/versions/node/v12.14.1/lib/node_modules/@ionic/cli)
   Ionic Framework               : @ionic/angular 5.2.2
   @angular-devkit/build-angular : 0.901.9
   @angular-devkit/schematics    : 9.1.9
   @angular/cli                  : 9.1.9
   @ionic/angular-toolkit        : 2.1.1

Cordova:

   Cordova CLI       : 10.0.0-dev (cordova-lib@10.0.0-dev)
   Cordova Platforms : Warning: using prerelease version 10.0.0-dev (cordova-lib@10.0.0-dev), ios 5.1.1
   Cordova Plugins   : cordova-plugin-ionic-keyboard 2.2.0, cordova-plugin-ionic-webview 4.1.3, (and 4 other plugins)

Utility:

   cordova-res (update available: 0.15.0) : 0.9.0
   native-run (update available: 1.0.0)   : 0.3.0

System:

   Android SDK Tools : 26.1.1 (/Users/niklasmerz/Library/Android/sdk)
   ios-deploy        : 1.10.0
   ios-sim           : 8.0.2
   NodeJS            : v12.14.1 (/Users/niklasmerz/.nvm/versions/node/v12.14.1/bin/node)
   npm               : 6.14.5
   OS                : macOS Catalina
   Xcode             : Xcode 11.5 Build version 11E608c

[BerkeAras]

AAAND an issue again: in iOS 14 Beta 5 ionic apps are reloading on some clicks (ion-item with href, ion-select) in multiple apps (one of the apps is my own, another app is from app store)

[liamdebeasi]

Thanks for the issue. This is a bug in WebKit, and I reported the issue to the WebKit team yesterday: https://bugs.webkit.org/show_bug.cgi?id=213495. The issue is that easing curves are ignored, and everything defaults to a linear easing curve.