A client can lose connectivity and drop all connections on the server side, but reconnect on the client side before all client side connections are marked closed. Then the client side thinks it has continuity but the server side has lost the channel context.

Fix this by marking first connections for a channel as such. If the service receives a new connection for a new channel, but the connection isn't marked as the first, then it's trying to establish a connection for an exiting channel on the client side. Reject the connection and let the client side connection close.