Open3D Visualizer not updating the window size correctly or at the right moment in the code execution.

### 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](https://www.open3d.org/docs/latest/getting_started.html#development-version-pip).
- [X] I have checked the [release documentation](https://www.open3d.org/docs/release/) and the [latest documentation](https://www.open3d.org/docs/latest/) (for `main` branch).

### My Question

I am facing this issue while my Open3D version is 0.18.0. Open3D visualization window's height and width don't match the saved camera parameters from the viewpoint.json file, even after setting the window size directly. Here is my code snippet:
# initialize visualizer
self._vis = open3d.visualization.Visualizer()
self._vis.create_window(width=1920, height=1080, window_name="Open3D Viewer")
self._vis.set_full_screen(True)
self._vis.get_render_option().background_color = np.asarray([0, 0, 0])