ID 524957 - Patch labels do not always update to show Channel resolution

Problem summary
Patch labels do not always update to show Channel resolution
 
Customer reported version
Mari 5.0v4
 
Customer reported platform
n/a
 
Steps to reproduce
 
1) Open any project

2) Create two Paint nodes and connect them to a Merge node
 
3) Connect the Merge node to a Channel node:
 

 
4) Switch to UV view
 
5) Switch Paint Targets between the two Paint nodes by clicking each alternately
 
Expected behaviour
The Patch labels should show the Channel resolution bracketed:
 

 
Actual behaviour
When the Paint node connected to the Merge's Base Input is the Paint Target, the Channel resolution is not shown:
 

 
Workaround
Unknown.
 
Reproduced by support
This bug has been reproduced in:
Mari 5.0v4 - Windows 10 - CentOS 7.9
Mari 4.0v1 - Windows 10
Mari 3.4v1 - Windows 10
Mari 3.3v1 - Windows 10
 
Unable to reproduce bug in:
Mari 3.2v1 - Windows 10
 
Earliest version tested
Mari 3.2v1 - This issue doesn't appear in this version and has regressed