ID 584613 - The parameter {attr:xyz} syntax does not resolve properly when soloing a material

Problem summary
The parameter {attr:xyz} syntax does not resolve properly when soloing a material
 
Customer reported version
Katana 6.5v1
 
Customer reported platform
CentOS7
 
Steps to reproduce
 
1) In Katana, open the attached scene MaterialSolo.katana.

2) Set your view flag (v) to the GafferThree node, enable live rendering in the Scene Graph by shift-clicking the Live Render option box next to the root location and then initiate a Live Render.

3) Drill down into the NetworkMaterialCreate node and enable material soloing by selecting the shader ball in the top right next to the output column.
 
4) Press the 1 and 2 keys to switch between the attr syntax (red backdrop) and directly setting the filename parameter (green backdrop).
 
5) Observe how the attr syntax shader information disappears from the render.
 
Expected behaviour
The material solo should resolve the attr syntax before rendering.
 
Actual behaviour
The attr syntax is not resolved and the material attribute is not properly set.
 
Workaround
A GenericOp can be placed at the end of the node stream with a MaterialSoloResolve opType to force a resolve before rendering.
 
Reproduced by support
This bug has been reproduced in:
Katana 7.0v2 - Windows 11 / Rocky 9
Katana 6.5v3 - Windows 11 / CentOS7
Katana 6.0v4 - Windows 11 / CentOS7
Katana 6.0v1 - Windows 11 / CentOS7
 
Unable to reproduce bug in:
Katana 5.0v7
 
Earliest version tested
Katana 5.0v7 - This feature did not exist before this version