In .NET Core 2.0, WebSocket.Open() does nothing, as the application exits the moment it's run. I use a task delay to hold it open for 1 second so I can see the output, but then the application immediately closes. Your example does not show this at all, so I can't help but think this is a bug.
Example: https://gist.github.com/IKnowBashFu/7f5a03373291ae90bbb16ef4d1e0caab
In .NET Core 2.0, WebSocket.Open() does nothing, as the application exits the moment it's run. I use a task delay to hold it open for 1 second so I can see the output, but then the application immediately closes. Your example does not show this at all, so I can't help but think this is a bug.