ID 525944 - Exported OBJ files separates into random mesh parts when importing groups as separate meshes or into another application.

Problem summary
Exported OBJ files separates into random mesh parts when importing groups as separate meshes or into another application. 
 
Customer reported version
modo.16.0v3
 
Customer reported platform
windows10
 
Steps to reproduce
 
1) Download and open the included scene file using the default settings.
 
2) Select the Mesh item and go to the Stats tab.
 
3) Expand Polygons and Part and notice that there's 6 different parts, and pressing '+' selects the part as expected.

4) Close the scene file.

5) Re-open the scene file and in the Wavefront Object Load Options window select Import Groups as Seperate Meshes.

 
6) Notice that the mesh is split into random parts.
 
Note: This also happens when importing it into another application such as Maya.
 
Expected behaviour
The separate meshes should be the set parts.
 
Actual behaviour
The mesh is split up randomly.
 
Workaround
Export as FBX.
 
Reproduced by support
This bug has been reproduced in:
16.0v3 - Windows 10, macOS 11.7 (Big Sur)
14.0v1 - Windows 10, macOS 11.7 (Big Sur)
 
Earliest version tested
14.0v1 - This issue appears to be in all tested versions of the product.