Mesh Import adds Extra Layer
This probably has a quick fix or a setting somewhere I've missed.
I have two Blender meshes and on import one creates a hierarchy of the main object and then the mesh as a sub-layer. This is what I want as materials and colliders are added to the top layer object. The other Blender mesh imports as a main object, a sub-object, and then the mesh. This is problematic as materials and colliders end up added to the sub-object. Within Blender the hierarchy of both files appear to be equal with a single root object and the mesh below that.
In Unity, on the mesh that imports correctly selecting Preserve Hierarchy creates the object, sub-object, mesh setup which mirrors the problematic layout. On the mesh which has this undesired hierarchy turning off Preserve Hierarchy doesn't make any change. In both cases Materials, Rigs, and Animation are all ignored on import.
What have I missed? Thanks!