### 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

/
} else {
					if (p_type != VisualShader::TYPE_FRAGMENT && p_type != VisualShader::TYPE_LIGHT) {
						j++;
						continue;
					}
				}
			} else {
				if (mode == VisualShader::VARYING_MODE_FRAG_TO_LIGHT) {
					if (p_type != VisualShader::TYPE_FRAGMENT) {
						j++;
						continue;
					}
				} else {
					if (p_type != VisualShader::TYPE_VERTEX) {
						j++;
						continue;
					}
				}
			}
			if (varying->get_varying_name() == varying->get_varying_name_by_index(i)) {
				to_select = i - j + 1;
			}
			add_icon_item(type_icon[varying->get_varying_type_by_index(i)], varying->get_varying_name_by_index(i));
		}
		if (to_select >= 0) {
			select(to_select);
		}
	}
};
class VisualShaderNodePluginParameterRefEditor : public OptionButton {