Spatial Mapping- GPU instance objects doesn't move

Hi

I'm trying to render a 3d point clouds on a surface. So far, I achieved 3d point clouds rendering and spatial mapping. As it showed below,

I used the sample program "MR Spatial 230". It recognized the local surface including floors and tables. And rendered a projector with the sun on the floor and a picture on the wall. You can also find my rendered 3d map on the above picture.
When I move the projector, the sun would the projector. However, my rendered 3d point cloud(under the same prefab as the sun) never moved. I also want to render the 3d map on the recognized floor. Is there anyone know how to check this problem?

I use Unity 2018.4.4 + Visual Studio 2019. And the prefab I used is as below,

In rendering the 3d map, I used

Code (CSharp):

1. DrawMeshInstanced

to render each point cloud as the same mesh, with a different color. It's strange that the sun follows projector coordinator, while 3d map cannot follow the coordinator change.

Thanks
Glen