### Godot version

v4.2.beta2.official [f8818f85e]

### System information

Windows 10, 64bit

### Issue description

Some times can't add node in visualshader editor

### Steps to reproduce

1. Open a VisualShader file for edit.
2. Click the `Add Node...` button, it will popup menu, it is OK.
3. Direct close the menu.
4. Clikd the `Add Node...` again, the menu can't popup.
![GIF](https://github.com/godotengine/godot/assets/35988767/1326c63e-3e05-4423-9ec7-7ce305b3f4f5)

### Minimal reproduction project

/
int offset = 0;
	if (mode & MODE_FLAGS_PARTICLES) {
		offset = 3;
		if (p_id + offset > VisualShader::TYPE_PROCESS) {
			custom_mode_box->set_visible(false);
			custom_mode_enabled = false;
		} else {
			custom_mode_box->set_visible(true);
			if (custom_mode_box->is_pressed()) {
				custom_mode_enabled = true;
				offset += 3;
			}
		}
	} else if (mode & MODE_FLAGS_SKY) {
		offset = 8;
	} else if (mode & MODE_FLAGS_FOG) {
		offset = 9;
	}
	visual_shader->set_shader_type(VisualShader::Type(p_id + offset));
	_update_nodes();
	_update_graph();
	graph->grab_focus();
}
void VisualShaderEditor::_custom_mode_toggled(bool p_enabled) {