Hey @learningelastic!
First, thank you for such a great explanation and even a video recreating your problem! That makes discussion much easier for sure.
I'm going to wipe out my environment and rebuild using your steps to try recreate the issue myself.
if you access http://localhost:8000 from your browser - does the sample app load?
if you're able to interact with the web app, do any additional logs show up on the container?