Bug: Stream of new messages does not emit all new messages

[bselwe]

Describe the bug

When the stream of messages streamBatchMessages is idle for 5-15 minutes (there is no new message received within that time), it sometimes fails to emit all new messages by skipping the first few messages.

Expected behavior

The stream of messages streamBatchMessages delivers all new messages in the given conversations.

Steps to reproduce the bug

listenToMessages(List<xmtp.Conversation> conversations) {
  recovery.cancel("messages");
  messagesSubscription?.cancel();
  messagesSubscription = client.streamBatchMessages(conversations).listen(
    (newMessage) async {
      debugPrint(
        '${DateTime.now()} [Conversations]: New message from ${newMessage.sender}: ${newMessage.content}',
      );

      send(NewMessageResponse(newMessage));
    },
    onError: (_) {
      recovery.cancel("messages");
      messagesSubscription?.cancel();
      recovery.attempt("messages", () => listenToMessages(conversations));
    },
  );
}

For recovery, see this.