(2018.3.6f1) Blender to Unity ultra simple basic mesh collider

Hi!

I've made a simple project:

- Created a cube in blender
- Created a project in Unity
- Added the cube from blender
- Created an empty, called it "BackgroundContainer"
- Created a cube, called it "BackgroundCubeStop" with a C# script:
- Created an empty, called it "BackgroundController" with a C# script: this script has public "GameObject[] Background prefabs" where I put all the Prefabs I want to be instantiated. Then the script, in update, move all those cubes on a line until they hit the BackgroundCubeStop then they start over from their start position.

Very simple right?

This is working with basic cubes that have a Box collider.

Now I want to modify a bit the cube to make it look like this:



I've done it, and asked Unity do Generate colliders + Preserve Hierarchy like this:




And this doesnt work. I can't explain it better than sharing my very simple + basic project:

- You can download the project here, open it, then:
- double-clic on the scene to open it
- click on `BackgroundCubeStop` to make is visible in the Scene above
- then click "play", you'll see the problem!