How to reproduce:
1. Open the user's attached "SGMaster.zip" project
2. Add URP, ShaderGraph, VFX Graph packages from the Graphics repo (4a4b558 commit)
3. Fix all the errors from the Console by commenting out the lines
4. Open the "Builtin Shader Graph" Shader Graph
5. Select the "Shader Graphs_Builtin Shader Graph" Material in the Project window
6. Observe the Inspector

Expected result: Property order is the same as in the Shader Graph's Blackboard
Actual result: Property order is ignored from the Custom Editor GUI in the Material Inspector

Reproducible with: 12.0.0 (2021.2.0a17)
Could not test with: 11.0.0 or lower (Due to the project errors)