Ошибка декодирования MessagePack при отправке пакета с сервера C++ на сервер NodeJs

I got problem when I tried sended some User-defined Class from C++ server to Nodejs Server By MessagePack .

If I defined a variable to zero in my class then the decode will be broken.
But If I defined a variable not equal zero then it will works fine.

Я запутался в результате, и вот что я делаю:

//The class I tried to send
class MPTest
{
public:
    MPTest(void);
    ~MPTest(void);
    int ObjA;
    MSGPACK_DEFINE(ObjA);
}; 

//sending by curl lib
int httpConnecter::post(MPTest *pNode)
{
    CURL *curl;
    CURLcode res;
    curl_global_init(CURL_GLOBAL_ALL);
    curl = curl_easy_init();
    std::vector<MPTest> vec;
     vec.push_back(*pNode);
    msgpack::sbuffer sbuf;
    msgpack::pack(sbuf, vec);

    msgpack::object_handle oh = msgpack::unpack(sbuf.data(), sbuf.size());
    msgpack::object deserialized = oh.get();
    std::vector<MPTest> unpackVec;
    deserialized.convert(unpackVec);

    if(curl) {
        curl_easy_setopt(curl, CURLOPT_URL, "http://localhost:3000/");
        curl_easy_setopt(curl, CURLOPT_POSTFIELDS, sbuf.data());
        fprintf(stderr, "check sbuf data: %s\n", sbuf.data());

        /* Perform the request, res will get the return code */ 
        res = curl_easy_perform(curl);
        /* Check for errors */ 
        if(res != CURLE_OK)
            fprintf(stderr, "curl_easy_perform() failed: %s\n", curl_easy_strerror(res));

        /* always cleanup */ 
        curl_easy_cleanup(curl);
    }
    return 0;
}

//My Nodejs server

const Hapi = require('hapi');
const MessagePack = require('what-the-pack');
const { encode, decode } = MessagePack.initialize(2**22);

const init = async () => {

    const server = Hapi.server({
        port: 3000,
        host: 'localhost'
    });

    server.route([{
        method: ['PUT', 'POST'],
        path: '/',
        handler: (request, h) => {
            try{
                console.log('1',request.payload);
                console.log('2',Buffer.from(request.payload));
                console.log('3',decode( request.payload));
            }catch(e){
                console.log('test!!!',e)
            }

            return 'Hello World from post!';
        },
        config: {
            payload: {
                output: 'data',
                parse: false
            }
        }
    }]);

    await server.start();
    console.log('Server running on %s', server.info.uri);
};

process.on('unhandledRejection', (err) => {

    console.log(err);
    process.exit(1);
});

init();

И когда я ставлю классу ненулевое значение. Он работал хорошо:

MPTest *a = new MPTest();
a->ObjA = 1;
   
httpConnecter *hConnecter = new httpConnecter();
   
hConnecter->post(a);

//Nodejs Result:
<Buffer 91 91 01 cd cd cd cd cd cd cd cd cd cd cd cd cd cd cd cd cd cd cd cd cd cd cd cd cd cd cd cd cd cd cd cd cd cd cd cd cd cd cd cd cd cd cd cd cd cd cd ... >

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Но если я присвою классу нулевое значение. И Он сломан...

MPTest *a = new MPTest();
a->ObjA = 0;
   
httpConnecter *hConnecter = new httpConnecter();
   
hConnecter->post(a);

//Nodejs Result:
<Buffer 91 91>
Error: @internalDecode : Error decoding value.
at internalDecode (D:\Pusher\PusherTestServer\node_modules\what-the-pack\index.js:550:13)
    at internalDecode (D:\Pusher\PusherTestServer\node_modules\what-the-pack\index.js:373:22)
    at internalDecode (D:\Pusher\PusherTestServer\node_modules\what-the-pack\index.js:373:22)
    at decode (D:\Pusher\PusherTestServer\node_modules\what-the-pack\index.js:556:20)
    at handler (D:\Pusher\PusherTestServer\dist\hapiHttpServer.js:21:33)
    at module.exports.internals.Manager.execute (D:\Pusher\PusherTestServer\node_modules\hapi\lib\toolkit.js:31:106)
    at Object.internals.handler (D:\Pusher\PusherTestServer\node_modules\hapi\lib\handler.js:46:48)
    at exports.execute (D:\Pusher\PusherTestServer\node_modules\hapi\lib\handler.js:31:36)
    at Request._lifecycle (D:\Pusher\PusherTestServer\node_modules\hapi\lib\request.js:312:68)
    at <anonymous>

Кто-нибудь знает, в чем проблема?

curl_easy_setopt(curl, CURLOPT_POSTFIELDSIZE, sbuf.size());

<Buffer 91 92 00 >
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