ID 521778 - Only one instance array is created for USD PointInstancers without a "prototypes" group

Problem summary
Only one instance array is created for USD PointInstancers without a "prototypes" group.
 
For example, the island-usd-v2.0 island.usda /island/isBeach/geometry/xgShells/instancer only creates one instance array location in Katana despite having multiple instance arrays:

 
Customer reported version
katana.n_a
 
Customer reported platform
centos7
 
Steps to reproduce

1. Download the USD Moana Island Scene: https://disneyanimation.com/resources/moana-island-scene/.
2. Load island-usd-v2.0/island/usd/island.usda in usdview.
   Note: you may need to use the --norender argument to disable the Hydra Viewer.
3. Expand the location /island/isBeach/geometry/xgShells/instancer.
4. Start Katana and load the island.usda with a UsdIn node.
5. Expand the /root/world/geo/island/isBeach/geometry/xgShells/instancer.
    

Expected behavior
Instance source groups with instance arrays locations are created for every xgShells location.
 
Actual behavior
Only one xgShells instance source group with and instance array location is created.
 
Workaround
In the USD file, nest all locations in the PointInstancer under a "Prototypes" Scope location.
 
Reproduced by support
This bug has been reproduced in:
Katana 5.0v4 - Windows 10
Katana 5.0v1 - Windows 10
Katana 4.5v4 - Windows 10
Katana 4.5v1 - Windows 10
Katana 4.0v1 - Windows 10
Katana 3.6v1 - Windows 10
Katana 3.5v1 - Windows 10
 
Earliest version tested
Katana 3.5v1 - Katana USD Plug-in did not exist before this version