Cannot modify spatial data(walls and furniture) after room scanning on Quest 3

We need to set up an 11x11 meter area for an MR game, and our app will generate MR scene base on scene data.

Please find our scanning steps below:

1. Physical Space > Space Setup > Setup
2. Walk through the space for room scanning until the mesh polygon is fully covered
3. Once scanning is complete, the auto-generated walls and furniture appear in my view

However, the walls are not blue as usual, they are red. When I try to modify them, nothing happens(no pop-up window or any feedback at all).

I expected a pop-up window to confirm deletion or a ‘+’ symbol on the lower left/right to modify or add new walls, but nothing is triggered except for the setup completion pop-up to end the process (pop-up as image below).

I apologize for not having a capture during the scanning process. The image was captured in the “edit” managed spaces, where I can no longer modify or capture the red walls.

To clarify, this issue occurs after the room scanning is completed, but the auto-generated walls and furniture cannot be modified.

Could this be due to the high black ceiling?

Is there any way to force edit walls? Any workaround for this problem?
Thanks.