It looks like the logic that decides if a package is part of the project is case sensitive. Should it be ?
I have the reference in the elements file as
<NuGetReference Include="aKKa:[1.1.3]" />
Its able expand it in the project manager but in the nuget references dialog its not selected.
In the .nuget packages folder it contains “akka”, so if I change the reference to
<NuGetReference Include="akka:[1.1.3]" />
It shows up selected.