httpclient doesn't send correct number to webapi

I use angular httpclient to send data to asp.net core webapi, the data is personcontact which has contact_value, media, person_ID, person_contact_ID.. these data. On webapi, I can receive the string data(contact_value, media..) correctly, however, for the int data, I receive some 0x0000ce6 or 0x000.. something data(which is not I want..), could you please tell me how I can receive person_ID and person_contact_ID .. these int/number data correctly in webapi?

tableelement.ts

confirmEditCreate_AddPerson(): boolean {
    //_personService: TestRDB2Service;
    if (this.id == -1)
      return this.source.confirmCreate(this);
    else
      
      try {
        this._http.put("https://localhost:5001/" + 'api/TestRDB2/AddUpdatePerson_Contact/', this.originalData).subscribe();      
      } catch (e) {
        return e
      }
    return true;
      //return this.source.confirmEdit(this);
  }

Testcontact.Controllers

        [HttpPut]
        [Route("AddUpdatePerson_Contact")]
        public int AddUpdatePerson_Contact([FromBody] personcontact personcontact)
        {
            return objtestRDB2.AddUpdatePerson_Contacts(personcontact);
        }