macOS - On example capture current image not working

### Checklist

- [X] I have searched for [similar issues](https://github.com/isl-org/Open3D/issues).
- [X] For Python issues, I have tested with the [latest development wheel](http://www.open3d.org/docs/latest/getting_started.html#development-version-pip).
- [X] I have checked the [release documentation](http://www.open3d.org/docs/release/) and the [latest documentation](http://www.open3d.org/docs/latest/) (for `master` branch).

### Describe the issue

I have used vis_gui.py for test, but the function del menu "Export current image" not working, return always a black screen

Screen open3d:

Captured image:

### Steps to reproduce the bug

```python
python3.9.12 -m venv venv --system-site-packages
source venv/bin/activate
pip install open3d==0.15.1
curl https://raw.githubusercontent.com/isl-org/Open3D/master/examples/python/visualization/vis_gui.py -o vis_gui.py
python vis_gui.py

---
Open any file and try export current image
```

### Error message

_No response_

### Expected behavior

_No response_

### Open3D, Python and System information

```markdown
- Operating system: macOS 10.15.7
- Python version: Python 3.9.12 `3.9.12 (v3.9.12:b28265d7e6, Mar 23 2022, 18:17:11)
[Clang 6.0 (clang-600.0.57)]`
- Open3D version: output from python: `0.15.1`
- Is this a remote workstation?: no
- How did you install Open3D?: pip
```

### Additional information

attach stl file used
[test-file.stl.zip](https://github.com/isl-org/Open3D/files/8402623/test-file.stl.zip)