Xamarin.forms: [Bug] Android Scrollview vertical Scrollbar is never visible.

[BasileusBasileon]

Description

On Android, the vertical scrollbar on a Scrollview will never be visible.

Steps to Reproduce

1. Create a blank Xamarin Forms project with Android.
2. Install any Xamarin Forms version from 3.5.0.129452 onwards.
3. Add a situation where you scroll a Scrollview vertically.

Alternatively, run the attached project.

Expected Behavior

The vertical Scrollbar of the Scrollview is visible according to the VerticalScrollBarVisibility.

Actual Behavior

The vertical Scollbar of the Scrollview is never visible.

Basic Information

• Version with issue: Any version from 3.5.0.129452 onwards
• Last known good version: 3.4.0.1039999
• IDE: Visual Studio 2017 Version 15.9.15
• Platform Target Frameworks:
  
  
  
  • Android: Android 8.1 (Oreo)
  
  
• Android Support Library Version: Tested on 27.0.2.1 and 28.0.0.1

Screenshots

Pre 3.5.0.129452:

3.5.0129452 and onwards:

Reproduction Link

Repro project:
MissingScrollbar.zip

[samhouts]

Same as https://github.com/xamarin/Xamarin.Forms/issues/7574?

[BasileusBasileon]

Same as #7574?

It appears to be the same, yes.

[samhouts]

I'm going to mark this one as a duplicate, even though it's older, because the other issue has some information about the possible root cause. Thanks!!!

[samhouts]

Duplicate of #7574