udpframed future select only first udp packet is received?

[skydig]

code just like following

  let mut framed_stream = UdpFramed::new(socket, ByteCodec).split().1.fuse();
    let mut kill_switch_endpoint = kill_switch_endpoint.fuse();

    loop {
        futures::select! {
            optional_packet = framed_stream.select_next_some() => {
                println!("{:?}",optional_packet);
                if let Ok(packet) = optional_packet {

                  //  let packet = packet?;
                  
                    if packet.0.len() > 0 {
                        process_udp_packet(&db, &packet.0, &peer_event_sink);
                    }
                } else {
                    info!("Client disconnect!");
                    break;
                }
            },
.....

I send same udp packet which length is one.
first packet is ok
but other packet , I got empty packet like following. why? thanks!!!
Ok(([], 127.0.0.1:56209))
Ok(([], 127.0.0.1:56209))
Ok(([], 127.0.0.1:56209))
Ok(([], 127.0.0.1:56209))

[skydig]

decode issue