Sorry for necro’ing this thread, but it was very relevant to me, so probably still relevant to others as well!
Basically, this was it as gagga Mentioned:
- If the editor is NOT set to “always load this project on startup”, starting the debugger from Visual Studio will start a “chooser” version of the editor. Once your project is selected, it shuts down the VS-debugged instance and proceeds to spawn another non-debugged by VS instance with your project.
You can see this in VS’s output, as soon as you choose the project in the selector all kinds of shutdown code gets called, and you are disconnected at that point.
It’s weird, but makes sense at the same time. This should probably be documented somewhere 
but hopefully this is helpful to someone else!