roslyn: WarningsAsErrors for CS8602 is not returning an error

Version Used: Visual Studio 2019 16.2.3 .NET Core: 3.0.0-preview8-28405-07

Steps to Reproduce:

For CS8602 I am not getting the expected errors when I add this code in the WarningsAsErrors section.

1. Modify the csproj as:

 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
     <OutputType>Exe</OutputType>
     <TargetFramework>netcoreapp3.0</TargetFramework>
+    <Nullable>enable</Nullable>
+    <WarningsAsErrors>CS8602</WarningsAsErrors>
   </PropertyGroup>
 </Project>

1. My sample application code is:

private static void PosibleDereferenceNullableReferenceTypes()
{
     string data = null;
     Console.WriteLine(data.Length);
}

Expected Behavior: An error when we build the project. Error CS8602 Dereference of a possibly null reference.

Note: When I put the codes CS8600, CS8603 or CS8604 into the WarningsAsErrors section, I receive the expected error messages in compilation time.

Actual Behavior: Warning CS8602 Dereference of a possibly null reference.

Updated information about this issue and its behavior:

If I write into the csproj: <WarningsAsErrors>CS8600;CS8602</WarningsAsErrors> I get the error messages for CS8600 (as expected) and for CS8602