Port 8888 not working (websockets)

Hey,

Thank you for this extended answer! That probably a big help for many.
I’m a bit busy this week, but I hope to continue playing with this in the weekend.

I made a whole front-end/back-end couple of years ago, but we’ve never got to use it because
the websocket weren’t reliable. On random moments the messages weren’t coming through.

So I wanted to do a clean setup to check if I can get it working again. I will follow your answer step-by-step and come with a response. But thanks in advance!