Ionic 3 - iOS device scrollbar visibility is inconsistant

Bug Report

Ionic Info

icli packages:

@ionic/cli-utils  : 1.19.2
ionic (Ionic CLI) : 3.20.0

global packages:

cordova (Cordova CLI) : 8.0.0 

local packages:

@ionic/app-scripts : 3.1.9
Cordova Platforms  : ios 4.5.4
Ionic Framework    : ionic-angular 3.9.2

Describe the Bug
In iOS touch devices, sometimes scrollbar is visible during scroll the content and sometimes not visible.

Steps to reproduce the behavior:

  1. Created a new ionic project with Tabs Starter Templates
  2. Add 1000 list on the contact page.
  3. Try to scroll the list.
  4. Switch different tabs and do the Step 3 again
  5. Expected Behavior
  6. Scrollbar is always visible during scroll the content.

Additional Context
Please find the attachment for more details

1 2

Any chance you found a fix for this issue? I am running into the same problem.