为什么VS 2019中的"Project Defaults“设置丢失？

<!-- 示例项目文件 (.vcxproj) -->
<Project DefaultTargets="Build" ToolsVersion="15.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
  <PropertyGroup>
    <ConfigurationType>Application</ConfigurationType>
    <PlatformToolset>v142</PlatformToolset>
  </PropertyGroup>
  <ItemGroup>
    <ClCompile Include="main.cpp" />
  </ItemGroup>
  <Import Project="$(VCTargetsPath)\Microsoft.Cpp.default.props" />
  <Import Project="$(VCTargetsPath)\Microsoft.Cpp.props" />
  <ImportGroup Label="ExtensionSettings">
  </ImportGroup>
  <ImportGroup Label="PropertySheets">
    <Import Project="$(UserRootDir)\Microsoft.Cpp.$(Platform).user.props" Condition="exists('$(UserRootDir)\Microsoft.Cpp.$(Platform).user.props')" Label="LocalAppDataPlatform" />
  </ImportGroup>
  <PropertyGroup Label="UserMacros" />
  <PropertyGroup>
    <OutDir>$(SolutionDir)$(Configuration)\</OutDir>
    <IntDir>$(Configuration)\</IntDir>
  </PropertyGroup>
  <ItemDefinitionGroup>
    <ClCompile>
      <WarningLevel>Level4</WarningLevel>
    </ClCompile>
  </ItemDefinitionGroup>
  <Import Project="$(VCTargetsPath)\Microsoft.Cpp.targets" />
  <ImportGroup Label="ExtensionTargets">
  </ImportGroup>
</Project>