Uno solution template missing Xaml IntelliSense until the .sln is reopened

[XiaotianNetlift]

Current behavior

When you create a new Cross-Platform App (Uno Platform) and open the MainPage.xaml, there is the Xaml IntelliSense support is missing.

Expected behavior

Xaml IntelliSense should just work.

How to reproduce it (as minimally and precisely as possible)

• create a Cross-Platform App (Uno Platform)
• open MainPage.xaml
• notice there is no Xaml IntelliSense support and the context switcher(?) dropdown is also missing:
  

You need to close all .xaml files and then reopen the solution to get IntelliSense back.

Environment

Nuget Package: n/a
Package Version(s): n/a

Affected platform(s):

• iOS
• Android
• WebAssembly
• WebAssembly renderers for Xamarin.Forms
• Windows
• Build tasks
• Solution Templates

Visual Studio:

• 2017 (version: )
• 2019 (version: )
• for Mac (version: )

Relevant plugins:

• Resharper (version: )

Anything else we need to know?

This is currently opened as a visual studio issue:

• https://developercommunity.visualstudio.com/content/problem/587976/xaml-intellisense-does-not-start-properly-on-proje.html
• [Epic] Opened Microsoft issues tracking #982