How to reproduce:
1. Open the project from the attached file "1238241.zip"
2. From Assets open "test" file and in the Visual Effect Graph window in the Output Particle Quad module, set Shader Graph to "shader"
3. From Assets open "shader" file and in the Shader Graph window press on the plus icon in the upper right corner of the blackboard and select Vector1
4. Press enter and then press Save Asset in the upper left corner of the Shader Graph window
5. Inspect the console

Expected result: No errors thrown in the Console
Actual result: "test : Exception while compiling expression graph: System.InvalidOperationException: Sequence contains no matching element" is thrown in the Console

Reproducible with: 8.0.1(2020.2.0a9, 2020.1.0b8), preview.13 - 9.0.0(2020.1.0b8)
Not reproducible with: 7.2.0(2019.3.11f1), 7.3.1(2020.2.0a9, 2019.3.11f1)
Could not test with: 4.10.0-preview(2018.4.22f1)(feature not introduced)

Notes:
- Rebinding the Shader Graph fixes the error
- Error is thrown only when adding a property(removing does not throw an error)
- The added property does not get updated in the VFX Graph Output Particle Quad module until Shader Graph is rebinded