### 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

/
Vector<Color> colors = {
					Color(0, 0, 0, 1),
					Color(0, 0, 0, 1),
					Color(0, 0, 0, 1),
					Color(0, 0, 0, 1)
				};
				draw_primitive(points, colors, uvs);
			}
		} break;
	}
}
void VisualShaderNodePortPreview::_bind_methods() {
}
String VisualShaderConversionPlugin::converts_to() const {
	return "Shader";
}
bool VisualShaderConversionPlugin::handles(const Ref<Resource> &p_resource) const {
	Ref<VisualShader> vshader = p_resource;
	return vshader.is_valid();
}
Ref<Resource> VisualShaderConversionPlugin::convert(const Ref<Resource> &p_resource) const {
	Ref<VisualShader> vshader = p_resource;
	ERR_FAIL_COND_V(!vshader.is_valid(), Ref<Resource>());
	Ref<Shader> shader;
	shader.instantiate();
	String code = vshader->get_code();
	shader->set_code(code);
	return shader;
}