OnlineSLAMRealSense doesn't actualise ?

### 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).

### My Question

Hi, I am actually working on the OnlineSLAMRealSense example with the Intel RealSense D455. So far, I was able to compile and launch it correctly but the program isn't working correctly. It only capture the first frame of the camera then stops totally without doing any reconstruction.

Anyone have a suggestion or an idea about this problem ? Thank you.