Cannot rename/change only the capitalisation of a property name when renaming a property in the Visual Effect Graph

Steps to reproduce:

1. Create a new Unity project using the Universal 3D template
2. Install the Visual Effect Graph package (com.unity.visualeffectgraph)
3. Create a new Visual Effect Graph (Assets > Create > Visual Effects > Visual Effect Graph)
4. Open the newly created Visual Effect Graph
5. Create a new Color property with the default name by clicking the "+" button in the Blackboard
6. Rename the "New Color" property to "NEW COLOR"
7. Observe the Blackboard

Actual results: The property is renamed to "NEW COLOR 1"

Expected results: The property is renamed to "NEW COLOR"

Reproducible with versions: 6000.6.0a7, 6000.6.1f1, 6000.7.0a6

Not reproducible with versions: 6000.0.0f1, 6000.0.83f1, 6000.3.24f1, 6000.5.11f1, 6000.6.0a6

Tested on (OS):  MacOS Silicon Tahoe 26.6.2, Ubuntu 24.04