wxWidgets eigenes Event wird nicht behandelt

#include "mainwindow.hpp"

wxDECLARE_EVENT(CUSTOMEVENT_SERIAL2, wxCommandEvent);

wxDEFINE_EVENT(CUSTOMEVENT_SERIAL2, wxCommandEvent);

MainWindow::MainWindow() : wxFrame(nullptr, 5, "test"){

  /*Steuerelemente*/

  wxBoxSizer* layoutMain = new wxBoxSizer(wxHORIZONTAL);

  /*Linkes Menu*/

  wxBoxSizer* layoutLeft = new wxBoxSizer(wxVERTICAL);

  layoutLeft->Add(new wxButton(this, 6, "button"), 1, wxEXPAND, 0);

  layoutMain->Add(layoutLeft, 1, wxEXPAND, 0);

  SetSizerAndFit(layoutMain);

  Bind(CUSTOMEVENT_SERIAL2, [this](wxCommandEvent& event) {

    std::string s("C998\n");

    recv.send(s.c_str(), s.length());

  });

  Bind(wxEVT_BUTTON, &MainWindow::onButton, this);

}

void MainWindow::onButton(wxCommandEvent& event) {

  wxCommandEvent evt2(this->GetId(), CUSTOMEVENT_SERIAL2);

  wxPostEvent(this, evt2);

}