Multiple controllers on one spline breaks stuff

[_Aka_]

Hi again
So here is how I fixed the issue:

1. Opened GameObject (1) prefab
   
2. Duplicated its obj 5 child. The duplicated object is called obj 5 (1)
   
3. Gave obj 5 (1) the same transform as obj 6
   
4. Gave obj 5 (1)'s child RetopoGroup6 the same name, material and mesh than obj 6's child RetopoGroup5
   
5. Deactivated obj6's game object
   
6. Saved the prefab
   
7. Went back to Scene 2, and hit play. Everything is working correctly
   

I attached the modified prefab just in case