matteocontrini This is actually intended, literally a feature not a bug. Stale connections staying open is a part of the memory leak issue from the main server. Closing connections after a while is an industry-standard practice with websockets.
There's no good solution that works for everyone. If we leave the connection (channel) open after the client stops responding, the server will be eventually bogged down with connections and we can't guarantee the client won't attempt to open a new connection as opposed to the old one when it reconnects. If we close the connection after no response, the client will lose real-time features until they refresh the page.