VS2019: Choose - When Condition=" '$(Configuration)'=='MyConfig' " not working anymore

I have a configuration named "local". This configuration compiles and links all my custom libraries with my application:

 <Choose>

   <WhenCondition="'$(Configuration)' == 'Local'">

     <ItemGroup>

       <ProjectReferenceInclude="..\..\..\..\Komponenten2\Idw.MvcLib\trunk\_apl\Idw.MvcLib.csproj">

         <Project>{751101e1-6d1d-4450-b647-8042ddd1d187}</Project>

         <Name>Idw.MvcLib</Name>

       </ProjectReference>

       <ProjectReferenceInclude="..\..\..\..\Komponenten2\LINQtoCSV\trunk\_apl\LINQtoCSV.csproj">

         <Project>{07058bf9-6f86-40ff-ae33-2a4f89b5758a}</Project>

         <Name>LINQtoCSV</Name>

       </ProjectReference>

     </ItemGroup>

   </When>

   <Otherwise>

     <ItemGroup>

     </ItemGroup>

   </Otherwise>

 </Choose>

With other configurations ("test", "production") these libraries are referenced by Nuget with the inversed condition:

   <ReferenceInclude="Idw.MvcLib, Version=2017.3.0.3, Culture=neutral, processorArchitecture=MSIL"Condition="'$(Configuration)' != 'Local'">

     <HintPath>..\packages\Idw.MvcLib.2017.3.0.3\lib\net461\Idw.MvcLib.dll</HintPath>

   </Reference>

With Visual Studio 2019 it takes always the NuGet reference instead of the project ref. I noticed it when I am trying to debug. The debugger issues a "Just My Code Warning": "You are debugging a Release buld of xxx.dll. Using Just My Code with Release builds using compiler optimizations results in a degrades debugging experience (e.g. breakpoints will not be hit)" With Visual Studio 2017 the same project works fine.