Node inspector offline?

Question

I am writing a nodejs application and I am relying heavily on the node inspector (specific the Node Inspector Manager (NiM). I would like to work on my application and use the inspector in Chrome, even without a live wifi or internet connection. Its a given of course that the rest of my app can indeed be worked on without a live internet connection.

When I disconnect my internet on my mac, and try to load the inspector, I get chrome's "no internet" page from within the devtools:

However I can see that my application is running just fine when I view it in the terminal.

My script to run my app with the inspector on is node --inspect -r tsconfig-paths/register -r ts-node/register ./src/server.ts (some extras in there for typescript and babel). When I run it, I see Debugger listening on ws://127.0.0.1:9229/4478a0d7-e8a3-4315-8d2e-069a4e1e6389. I then navigate to https://chrome-devtools-frontend.appspot.com/serve_file/@a6b12dfad6663f13a7e16e9a42a6a4975374096b/inspector.html?experiments=true&v8only=true&ws=localhost:9229/4478a0d7-e8a3-4315-8d2e-069a4e1e6389 (not manually, I've set up NiM to open this open automatically).

Is this a known bug? Is there some setting I need to adjust? How can I utilize the node-inspector in Chrome with applications running locally, even if wifi is not present?