I have built a production ready app using Flask socketio in the backend and socketio in the frontend (browser app).

In development the client would connect to the socket perfectly, but in production, I keep getting the following message in the client:

failed: WebSocket is closed before the connection is established

Eventually the client connects ant the messages stop appearing. But sometimes, even after the client connects, the connection drops and the messages start appearing again.

Does anyone have any idea of what can be causing that issue?

I have found multiple posts here where this issue happens and the client is never able to connect, but that is not the case here, it appears that the connection is just somewhat slow and I have no idea why...