ID 366551 - Polygon normals on a text operator are inconsistent when frozen

Problem summary
In the attached scene, polygon normals on a text operator are inconsistent when frozen. This was not reproducible in a clean scene.  

Customer reported version
Modo 12.1v2

Customer reported platform
Windows 10 

Steps to reproduce
1) Open the attached scene in Modo. 

2) Select the text under "description" in the Item list.  

3) Change the viewport to render with Gooch Tone Shading. 

4) Scrub the timeline to frame 5. 

5) The text should now be blue instead of yellow, where polygon normals are inverted in the Z-axis.

Workaround
Unknown.

Reproduced by support
This bug has been reproduced in:
Modo 12.1v2 - Windows 10 - CentOS 7 - MacOSX 10.13
Modo 12.0v1 - Windows 10 - MacOSX 10.13 
Modo 11.2v3 - Windows 10 
Modo 11.1v1 - Windows 10
Modo 11.0v3 - Windows 10
Modo 10.2v4 - Windows 10 - CentOS 7

NOTE: This issue started to occur in Modo 12.0v1 on MacOSX 10.3. 

​Unable to reproduce bug in:
Modo 11.2v3 - MacOSX 10.13  
Modo 11.1v1 - MacOSX 10.13  
Modo 11.0v3 - MacOSX 10.13  
Modo 10.2v4 - MacOSX 10.13  

Earliest version tested:
Modo 10.2v4 - This issue appears to occur in all versions on Windows 10 and CentOS.

NOTE: This issue does not appear to occur on MacOSX 10.13 in Modo 10.2v4. ​​​

Expected behaviour
Polygon normals should be consistent when a text operation is frozen. 

Actual behaviour
Polygon normals seem to be inconsistent when a text operation is frozen. In this case, they are inverted along the z-axis.