I don’t think that’s how it works. I’ve experienced disconnection issues and any messages sent in that period would not be received/sent until the connection was re-established. Furthermore, you can only change servers for receiving messages and it takes ages if ever.
If you lose your internet connection, messages will obviously not be sent until you regain your connection. However, if a Simplex server stops working, another one will be chosen, but not to continue the connection; instead, a new connection will be established. This is the behavior I have also observed with calls: the conversation drops, and I have to call back, connecting to a different server.
Please only use English on this forum.
Obviously I can’t send messages without network connection.
So contacts are server independent?
No, if a receiving/sending server is down you need to re-establish connection with your contact using a QRcode or invitation link.