The code in the repo is not-so-minimal, there is a lot going on with how the pages are loaded. I would suggest the following steps for debugging,
-
Run the quart server in a separate terminal (it is unclear to me, if it is started at all in your current code)
-
Move the websocket component into the main layout
If the above does not work, start from the working example, then perform small modifications towards the multi page setup while continuously testing the functionality.