Publish Website Does not Use Transformed web.config - visual-studio-2019

Question

I created a solution containing a website (not WebApp) with VS Express 2013. I use a web.Release.config file for the publish process. That worked well with VS 2013.
Now that I changed to VS 2019 Community, web.Debug.config was used for the web.config transformation though the publish was done for "Release". I suppose that is because in the configuration manager only "Debug" is possible for any configuration.
In another thread I found that I had to change website.publishproj from Debug to Release:
<Configuration Condition=" '$(Configuration)' == '' ">Release</Configuration>
Now, web.Release.config is used for the transformation:
"web.config" wurde mithilfe von "C:\Users\<project path>\Web.Release.config" in "C:\Users\<some temporary path>\obj\Release\TransformWebConfig\transformed\web.config" transformiert.
This file actually has the changes applied that are needed for Release.
However, in the destination directory web.config does not contain these changes. It seems to be the original web.config without transformation.
What must I do to make Publish copy the transformed web.config?
This is my .pubxml file:
<?xml version="1.0" encoding="utf-8"?>
<!--
Auto generated comment...
-->
<Project ToolsVersion="4.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
<PropertyGroup>
<WebPublishMethod>FileSystem</WebPublishMethod>
<PublishProvider>FileSystem</PublishProvider>
<LastUsedBuildConfiguration>Release</LastUsedBuildConfiguration>
<LastUsedPlatform>Any CPU</LastUsedPlatform>
<SiteUrlToLaunchAfterPublish />
<LaunchSiteAfterPublish>True</LaunchSiteAfterPublish>
<ExcludeApp_Data>False</ExcludeApp_Data>
<publishUrl>C:\Inetpub\vhosts\<website name>.com\httpdocs</publishUrl>
<DeleteExistingFiles>True</DeleteExistingFiles>
</PropertyGroup>
and here is website.publishproj:
<Project ToolsVersion="4.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
<PropertyGroup>
<Configuration Condition=" '$(Configuration)' == '' ">Release</Configuration>
<Platform Condition=" '$(Platform)' == '' ">AnyCPU</Platform>
<ProductVersion>10.0.30319</ProductVersion>
<SchemaVersion>2.0</SchemaVersion>
<ProjectGuid>{45ff7195-6038-4b17-91ce-611a467ac837}</ProjectGuid>
<SourceWebPhysicalPath>$(MSBuildThisFileDirectory)</SourceWebPhysicalPath>
<SourceWebVirtualPath>/(Source Path Name)</SourceWebVirtualPath>
<TargetFrameworkVersion>v4.0</TargetFrameworkVersion>
<SourceWebProject>http://localhost:56406</SourceWebProject>
<SourceWebMetabasePath>/IISExpress/7.5/LM/W3SVC/2/ROOT</SourceWebMetabasePath>
</PropertyGroup>
<PropertyGroup>
<VisualStudioVersion Condition="'$(VisualStudioVersion)' == ''">10.0</VisualStudioVersion>
<!-- for VS2010 we need to use 10.5 but for VS2012+ we should use VisualStudioVersion -->
<WebPublishTargetsVersion Condition=" '$(WebPublishTargetsVersion)' =='' and '$(VisualStudioVersion)' == 10.0 ">10.5</WebPublishTargetsVersion>
<WebPublishTargetsVersion Condition=" '$(WebPublishTargetsVersion)'=='' ">$(VisualStudioVersion)</WebPublishTargetsVersion>
<VSToolsPath Condition="'$(VSToolsPath)' == ''">$(MSBuildExtensionsPath32)\Microsoft\VisualStudio\v$(WebPublishTargetsVersion)</VSToolsPath>
<_WebPublishTargetsPath Condition=" '$(_WebPublishTargetsPath)'=='' ">$(VSToolsPath)</_WebPublishTargetsPath>
<AssemblyFileVersion Condition="'$(AssemblyFileVersion)' == ''">1.0.0.0</AssemblyFileVersion>
<AssemblyVersion Condition="'$(AssemblyVersion)' == ''">1.0.0.0</AssemblyVersion>
</PropertyGroup>
<ItemGroup>
<AssemblyAttributes Include="AssemblyFileVersion">
<Value>$(AssemblyFileVersion)</Value>
</AssemblyAttributes>
<AssemblyAttributes Include="AssemblyVersion">
<Value>$(AssemblyVersion)</Value>
</AssemblyAttributes>
</ItemGroup>
<ItemGroup>
<ProjectReference Include="..\Accessories\Lib\Runtime\BaseLib\BaseLib.csproj">
<Project>{8A827F3E-CA83-4765-988D-937B0B608201}</Project>
<Name>BaseLib</Name>
</ProjectReference>
<ProjectReference Include="..\Accessories\Lib\Runtime\Config\Config.csproj">
<Project>{1B78D777-B4F8-4CEA-9A4F-554807D1E5BF}</Project>
<Name>Config</Name>
</ProjectReference>
<ProjectReference Include="..\Accessories\Lib\Runtime\GardenLib\GardenLib.csproj">
<Project>{30B09928-B911-4803-982F-519C4CDB8860}</Project>
<Name>GardenLib</Name>
</ProjectReference>
</ItemGroup>
<Import Project="$(_WebPublishTargetsPath)\Web\Microsoft.WebSite.Publishing.targets" />
</Project>

Answer 1

After I got some more problems publishing my website, I switched back to VS2013 Express where my publish process works well as it did before.
Maybe it's a bug in Visual Studio?