ID 553136 - Multiple assemblies in a scene causes unexpected results

Problem summary
Multiple assemblies in a scene causes unexpected results.
 
Customer reported version
Modo 16.1v7
 
Customer reported platform
Windows 10
 
Steps to reproduce
1) Download attached file and open it in Modo.

2) On the Stairs mesh, select the Controller.

3) Open the pop-up menu and under the Stair_Controller tab, change the stair type from 0 to 1 and observe the results in the 3D Viewport.
 
Expected behavior
Multiple assemblies in a scene should continue to work as expected.
 
Actual behavior
Multiple assemblies in a scene do not continue to work as expected.
 
Workaround
Unknown.
 
Reproduced by Support in:
Modo 16.1v7 - Windows 11, macOS 11.7 Big Sur
Modo 16.0v1 - Windows 11, macOS 11.7 Big Sur - regression
 
Unable to reproduce bug in:
Modo 15.2v4 - Windows 11, macOS 11.7 Big Sur
 
Earliest version tested
Modo 15.2v4 - This issue doesn't appear in this version and has regressed.