ID 580452 - Subdividing a USD Object Version with multiple gprims in an Alembic Object leads to disappearing faces and other broken behaviours

1. Launch Mari and create a new Project using an Alembic geometry (attached).
    
2. In the Objects palette, right-click the Object and select Add Object Version.
    
3. Add a USD file as the new Object Version (attached). To reproduce, this must be a file with multiple meshes in its geometry tree view:
   
   

   

   
    
4. Switch to the USD version by selecting Objects > Geometry > Version.
    
5. Select Object > Subdivision > Subdivide > Ok to subdivide the USD Object.
    
6. If faces don't immediately disappear, move the camera around, perform face selections, or switch between subdivision levels until they do.

 
NOTE: Support tested with various other combinations of steps and file types. Only this specific "Alembic to USD" setup causes this issue.
 
Expected behaviour
The USD Object should be subdivided with no issues.
 

 
Actual behaviour
Subdivision is performed, and at Level 0 the Object looks fine. But at subdivided levels, a random amount of the geometry's faces disappear. The faces that are visible/invisible can change randomly by moving the camera, changing the subdivision level, performing selections, or changing which node is being viewed. 
 

 
 
Once the Project is in this state, a few other behaviours can be noticed:
 

• Face Selection: Nothing happens, or it selects the wrong faces, or it works fine.
   
• Selection > Select All: Typically makes more faces disappear, and then it's typically impossible to remove the selection highlight color.
   
• Subdivision: Sometimes it happens it subdivides in the backgorund, even though Support selects Ok instead of Background.
   
• Painting: It's possible to paint in areas that wold be hidden if faces weren't missing.