Does Mesh Collider have a minimum scale????

I have the following heirachy:

World

Camera
Tree
Cube
Sphere

The tree has a mesh collider. When I set the scale of world below 0.01f then the mesh collider on the tree stops working for a raycast from the camera. But the colliders on the cubes and trees work fine. Is there any explanation for this?

I would like the colliders to work a for a scale of about 0.001f at least.

(Obviously changing the scale of the world in this example doesn’t affect the appearance of anything. But I need to do this for other reasons).

Edit: I can fix the problem by using

Universe

World

Camera
Tree
Cube
Sphere

and setting the scale of the universe to be 1000f. So the world size of the meshColliders is 1.

Does this mean there is a minimum world scale allowable for meshColliders?

yes