WebSocket connection to 'wss://s-euw1b-nss-201.europe-west1.firebasedatabase.app/.ws?v=5&s=WKO6LXOUdJD93R9BqJdhZPJaZb2itgms&ns=oshop-dc8f0-default-rtdb' failed:
This is a known issue. The Firebase client attempts to establish a real-time connection to the Firebase servers using multiple methods. If one of those methods succeeds before the Websocket does, we cancel the Websocket and you see that warning. You can safely ignore the error.