ID 536739 - NMC - Sidebar material collapse state lost after opening a Katana project

Problem summary
When using NMC with multiple materials, the sidebar collapse state is lost for all materials on the scene when the scene is re-open. 
 
Customer reported version
Katana.6.0v1
 
Customer reported platform
 
Steps to reproduce
 

1. Add an NMC node, add a few new NetworkMaterials via the parameters tab
2. Enter the NMC node graph, collapse the network materials in the sidebar
3. Save the Katana project
4. Start a new instance of Katana and open the previous scene

 
Expected behaviour
Collapse state is remembered when returning to the graph after opening a scene.
 
Actual behaviour
All the materials are expanded
 
Workaround
Unknown.
 
Reproduced by support
This bug has been reproduced in:
Katana 6.0v1 - CentOS 7 - Windows 10
Katana 5.0v5 - CentOS 7
Katana 5.0v1 - CentOS 7
Katana 4.5v5 - CentOS 7
Katana 4.5v1 - CentOS 7 - Windows 10 - Regression
 
Unable to reproduce bug in:
Katana 4.0v8 - CentOS 7 - Windows 10
 
Earliest version tested
Katana 4.0v8 - This issue doesn't appear in this version and has regressed