ID 408792 - Incorrect display of Catmull Clark weight maps in 13.1v1.

Problem summary
Incorrect display of Catmull Clark weight maps in 13.1v1.

Customer reported version
modo.13.1v1

Customer reported platform
windows7

Steps to reproduce

1) Create a sphere.

2) Select the top vertex's and flatten inline.

3) Select the Sphere mesh and go to the Vertex Maps tab, expand the Weight Maps section and select Subdivision.

4) Go to properties and set the Catmull-Clark Render and Subdivision Level to 3.

5) Press the O key to open the 3D Viewport Properties, select the Active Meshes tab and enable Show Weightmaps.

6) Select the edges at the top of the sphere and press the Shift+W keys to active the Weight Tool and set the Weight value to 30%.

7) Press the Shift+Tab keys to change to Catmull-Clark subdivisions and notice that the weight map isn't contained at the edge.

13.1v1

13.0v1

Expected behaviour
The weight map should be contained at the edge in Catmull-Clark.

Actual behaviour
The weight map is spread across the polygons in Catmull-Clark.

Workaround
Unknown. 

Reproduced by support

This bug has been reproduced in:

13.1v1 - Windows 10 - MacOS 10.13 - Centos 7 -regression

Unable to reproduce bug in:
13.0v1 - Windows 10 - MacOS 10.13 - Centos 7

Earliest version tested

13.0v1 - This issue doesn't appear in this version and has regressed.