[Bug] PanGestureRecognizer not workingcorrectly in several scenarios and devices.

Description

PanGestureRecognizer is not working correctly (or as expected) in several scenarios and devices. In Android it seems to work correctly in most scenario except when ScrollView is present. In UWP sometimes does not recognize and fire Completed/Canceled event when leave the view doing gesture.

Steps to Reproduce

1. Download the allegate, compile and execute the TestApp.
2. Try to comment/uncomment some region in xaml where is present ScrollView.
3. See the behevior in some of the above described scenarios.

Expected Behavior

PanGestureRecognizer to work inside a ScrollView too, and always fire at least Completed/Canceled event when leave or exited the view during the gesture.

Actual Behavior

In some scenarios PanGestureRecognizer does not work correctly and is not fired event like Completed/Canceled as expected, this cause an issues in managing some GUI (or not) transitions.

Basic Information

• Version with issue: Xamarin.Forms, Version 4.3.0.947036.
• Last known good version: N.A.
• IDE: Visual Studio Community 2019, Version 16.3.7.
• Platform Target Frameworks:
  • Android: Android SDK Platform 28.
  • UWP: Build 18362 (version 1903).
• Nuget Packages:
  • Xamarin.Essentials, Version 1.3.1.
  • Xamarin.Android.Support.Core.Utils, Version 28.0.0.3.
  • Microsoft.NETCore.UniversalWindowsPlatform, Version 6.2.9.
• Affected Devices: Android, UWP.

Test

AppTest.zip