"focus-out-event" crashes application

[CapitaineJSparrow]

I tried to add a "focus-out-event" on a "GtkSearchEntry" but application is crashing from native code.

[INFO] loop.cc: QuitLoopStack: 173: calling (anonymous)
/home/sparrow/projects/app/node_modules/node-gtk/lib/overrides/Gtk-3.0.js:37
        originalMain()
        ^

TypeError: Cannot convert value "undefined" to type gboolean in signal "focus-out-event"
    at Function.main (/home/sparrow/projects/app/node_modules/node-gtk/lib/overrides/Gtk-3.0.js:37:9)
    at Object.<anonymous> (/home/sparrow/projects/app/app.js:40:5)
    at Module._compile (node:internal/modules/cjs/loader:1126:14)
    at Object.Module._extensions..js (node:internal/modules/cjs/loader:1180:10)
    at Module.load (node:internal/modules/cjs/loader:1004:32)
    at Function.Module._load (node:internal/modules/cjs/loader:839:12)
    at Function.executeUserEntryPoint [as runMain] (node:internal/modules/run_main:81:12)
    at node:internal/main/run_main_module:17:47

Here is the index (crashing when onSearchBarFocusOut is triggered in handlers)

const gi = require('node-gtk')
const path = require('path');
gi.startLoop();

const Gtk = gi.require('Gtk', '3.0');
const Gdk = gi.require('Gdk', '3.0');
Gtk.init();

// Load custom theme
const css_provider = new Gtk.CssProvider()
css_provider.loadFromPath(path.join(__dirname, 'resources', 'test.css'));
const context = Gtk.StyleContext
const screen = Gdk.Screen.getDefault();
context.addProviderForScreen(screen, css_provider, Gtk.STYLE_PROVIDER_PRIORITY_APPLICATION);

// Load UI file to GtkBuilder
const gladeFile = path.join(__dirname, 'resources', 'test.ui');
const builder = Gtk.Builder.newFromFile(gladeFile);
const win = builder.getObject('mainWindow');

// Animations
const searchButton = builder.getObject('searchButton');
const search = builder.getObject('search');

const handlers = {
    onSearchBtnClick: () => {
        searchButton.getStyleContext().addClass("search-button-open")
        search.getStyleContext().removeClass("search-hide")
        search.getStyleContext().addClass("search-open")
    },
    onSearchBarFocusOut: () => {
        console.log("Crash here")
    }
}

builder.connectSignals(handlers)

win.on('show', Gtk.main);
win.on('destroy', () => Gtk.mainQuit())
win.showAll();

here is glade file for reference

<?xml version="1.0" encoding="UTF-8"?>
<!-- Generated with glade 3.38.2 -->
<interface>
  <requires lib="gtk+" version="3.24"/>
  <object class="GtkImage" id="image1">
    <property name="visible">True</property>
    <property name="can-focus">False</property>
    <property name="icon-name">go-previous</property>
  </object>
  <object class="GtkImage" id="image2">
    <property name="visible">True</property>
    <property name="can-focus">False</property>
    <property name="icon-name">go-next</property>
  </object>
  <object class="GtkImage" id="image3">
    <property name="visible">True</property>
    <property name="can-focus">False</property>
    <property name="icon-name">system-search</property>
  </object>
  <object class="GtkWindow" id="mainWindow">
    <property name="can-focus">True</property>
    <property name="title">dqsdsdsq</property>
    <property name="window-position">center</property>
    <property name="default-width">1280</property>
    <property name="default-height">720</property>
    <child>
      <object class="GtkBox">
        <property name="visible">True</property>
        <property name="can-focus">False</property>
        <property name="valign">start</property>
        <property name="margin-start">8</property>
        <property name="margin-end">8</property>
        <property name="margin-top">8</property>
        <property name="margin-bottom">8</property>
        <child>
          <object class="GtkButton" id="backButton">
            <property name="name">backButton</property>
            <property name="visible">True</property>
            <property name="can-focus">True</property>
            <property name="receives-default">True</property>
            <property name="image">image1</property>
            <property name="always-show-image">True</property>
            <style>
              <class name="no-round-right"/>
            </style>
          </object>
          <packing>
            <property name="expand">False</property>
            <property name="fill">True</property>
            <property name="position">0</property>
          </packing>
        </child>
        <child>
          <object class="GtkButton">
            <property name="visible">True</property>
            <property name="can-focus">True</property>
            <property name="receives-default">True</property>
            <property name="image">image2</property>
            <property name="always-show-image">True</property>
            <style>
              <class name="no-round-left"/>
            </style>
          </object>
          <packing>
            <property name="expand">False</property>
            <property name="fill">True</property>
            <property name="position">1</property>
          </packing>
        </child>
        <child>
          <object class="GtkButton" id="searchButton">
            <property name="visible">True</property>
            <property name="can-focus">True</property>
            <property name="receives-default">True</property>
            <property name="margin-start">8</property>
            <property name="image">image3</property>
            <property name="always-show-image">True</property>
            <signal name="clicked" handler="onSearchBtnClick" swapped="no"/>
          </object>
          <packing>
            <property name="expand">False</property>
            <property name="fill">True</property>
            <property name="position">2</property>
          </packing>
        </child>
        <child>
          <object class="GtkSearchEntry" id="search">
            <property name="can-focus">True</property>
            <property name="hexpand">True</property>
            <property name="primary-icon-name">edit-find-symbolic</property>
            <property name="primary-icon-activatable">False</property>
            <property name="primary-icon-sensitive">False</property>
            <property name="placeholder-text" translatable="yes">Search for an application</property>
            <signal name="focus-out-event" handler="onSearchBarFocusOut" swapped="no"/>
            <style>
              <class name="search-hide"/>
            </style>
          </object>
          <packing>
            <property name="expand">False</property>
            <property name="fill">True</property>
            <property name="position">3</property>
          </packing>
        </child>
      </object>
    </child>
  </object>
</interface>