I have tried this a few different ways and it always seems to fail.
Create a new Blank Solution (my.solution.name). Then add a new ClassLibrary project (my.project.name) to the solution. This results in the solution explorer only showing my.project.name.
Create a new ClassLibrary (my.project.name) which should have my.project.name solution and my.project.name project. I only see my.project.name project.
Without the solution level I'm unable to add any new projects to my solution. This seems to have just started today.