Unmanaged constructed types and Visual Studio (possible bug?)

I downloaded the beta today to check if unmanaged constructed types are supported already (I read in another thread that they should be) but I’m getting this error in Visual Studio:

The code compiles and executes just fine in Unity. Both in Editor and in release.

I regenerated project files but it doesn’t seem to have had any effect. I believe I have the latest version of the Visual Editor Plugin (2.0.2).

Is this a bug or is there something else I could try to get rid of that error notification in VS?

The VS IDE support plugin (as of version 2.0.1) has functionality that forces generated .csproj files to use C# 7.3 when C# 8 support is detected. Until this is removed (or tweaked to only affect the appropriate versions of Unity), the simplest solution available is to downgrade to version 2.0.0.