Fix Laravel Broadcasting with Redis and Socket.IO Issue

We got a copy of online casino source code from the Internet and are trying to set up it on the server. It is written on JQuery & Laravel. Laravel-echo-server&redis&[login to view URL] is introduced for communication between client and server. The Nodejs package, laravel-echo-server&laravel-echo, is used to catch the frontend events and publish them into the redis. On the other hand, Laravel backend subscribes to the redis channel, process the events and response them. We've encountered issues with the communication between laravel-echo-server and redis. When we accessed our website on the browser, it infinitely repeated loading with the text "Failed to connect to the server. Retrying in 5 second(s)...", the laravel-echo-server log showed that it recieved the frontend ping event and published into the redis. However, nothing was found in the redis. It seems like the ping packet lost on the road from laravel-echo-server to redis because of misconfiguration. We need someone with relevant experience to save us and figure out the reason. You will get full access to our server and source code for debugging. Note: Althought the project is for an gambling website, it is not production environment , only for learning purpose. So it should not be an issue even if online gambling is forbidden by law of some nations