Shader Graph Enum Keyword Default Value changes after reordering Entries

Reproduction steps:
1. Create a new project
2. Create any Shader Graph (e.g. Create > Shader Graph > Blank Shader Graph)
3. Double-click the created Asset to open Shader Graph window
4. Click “Blackboard” button to open Blackboard Overlay
5. Press “+” button in the Blackboard and add Enum Keyword (Keyword > Enum)
6. Select Enum Keyword and change Default Value to a different Entry in the Graph Inspector Overlay (e.g. “B”)
7. Reorder selected Entry in the Entries list and observe Default Value setting

Actual result: Default Value changes to whichever Entry occupies the previously selected Entry position in the list
Expected result: Default Value remains assigned to the same Entry

Reproducible with: 6000.0.74f1, 6000.3.14f1, 6000.4.6f1, 6000.5.0b7, 6000.6.0a4

Reproduced on: Windows 11, macOS Tahoe 26.4 (M4)