Creating Sub Graph/ Sub Graph block of "System" properties without 'Spawn System" causes the editor to freeze

Steps to repro:
1. Create a new HDRP template project.
2. Project Window > Right Click > Create > Visual Effect
3. Double click on it to open the VFX editor
4. Select properties exclusively from 'System\ section
5. Righ Click > Create Sub Graph

Expected Result:
Sub Graph is created

Observed Result:
Editor Freezes

Reproducible On:
2020.2.0a5 with Package Version 8.0.1
2020.1.0b4 with Package Version 8.0.1

Not Reproducible in:
2020.2.0a5 with Package Version 7.3.1, 7.2.0, 7.1.8, 7.1.7

Environment:
Occurs only on Mac