Unexpected class name returned from $PropertyGrid.SelectedObject when run from a compiled executable

Tool: Visual Studio, Visual Studio Code, PSScriptPad, PowerShell Module
Version: 

I have some code that runs when the value within a PropertyGrid is changed. When I run this within a Visual Studio debug session everything works as expected and the corrected class name is returned.

But when I run the same code from the compiled executable, I get a weird, doted prefix to the name returned.

The class is very simple:
image

When I query it in the IDE with:

I get this:

From the EXE I get this:

Is this a bug or do I need to do something different in the build process?

These are the exe settings:
image