[Bug] UWP Shell Support Not Rendering and Mis-Rendering some Button Controls

Description

Using the default Xamarin Forms project template the UWP project runs but hides some elements (the "Add" item button in the upper right corner) and does some wonky layout on the Shell button navigation in the bottom. Also, probably worth noting the "indent" effect happening with the controls from top to bottom along the left-hand side of window.

See screenshots below.

Steps to Reproduce

1. Create a new Xamarin Forms project*
2. Update XF nuget to 4.3pre2
3. Add Blank UWP project
4. Set UWP to use XF per https://docs.microsoft.com/en-us/xamarin/xamarin-forms/platform/windows/installation/
5. Run Android and UWP.

*Used 2019 16.3.1

Expected Behavior

Have the corresponding "Add" button visible and functional See the Shell Navigation buttons on the same horizontal plane

Actual Behavior

The Add button is missing The Shell Navigation buttons are not rendering on the same horizontal plane, create "jaggy" layout.

Basic Information

• Version with issue: 4.3pre2
• Last known good version:
• IDE: VS 2019 16.3.1
• Platform Target Frameworks:
  • iOS:
  • Android:
  • UWP:
• Android Support Library Version:
• Nuget Packages:
• Affected Devices:

Screenshots

Working Almost there

Reproduction Link

The working solution to reproduce can be downloaded here:

https://versive-my.sharepoint.com/:u:/g/personal/dave_gerding_us/EYff_Veh9aZMhIWhsYzZ6xoB3Qn0tZrHZ0XRhBmiUGv4Ww?e=C1vaVi