...assemblies present at the root of lib folder without a target framework specific sub-folder are ignored. NuGet looks for a sub-folder matching the target framework moniker (TFM) corresponding to the project’s target framework and installs the matching assemblies into the project.
Are there any plans to update the .nuspec to place the dll in a target framework sub-folder?
Per the PackageReference migration documentation:
Are there any plans to update the .nuspec to place the dll in a target framework sub-folder?