You're actually doing what's in the link concerning Core and Local IIS debugging where the VS Web project is connected to the code local IIS is hosting?
How much data is being sent on the request?
Why can't you use VS debugging of hosted code on local IIS, which you can go to the browser address bar and make a request to a controller action method and see the response in the browser, by debug attaching to the WPW3.exe that is hosting the Web program and setting breakpoints?