On Reconverting "Subgraph Operator" Node, InvalidOperationException is thrown along with creating a duplicate Node of "Subgraph Operator" instead of replacing it, refer attached video

Steps to repro:
1. Create a new project
2. Windows > Package Manager > Visual Effects Graph > Install
3. Project > Packages > Visual Effect Graph > Editor > Templates > Open Simple Swarm Particle System
4. Add any "Node" to any Block
5. Select Node > right-click > Convert to Subgraph Operator > Save
6. Select same converted node > right-click > Convert to Subgraph Operator > Save > Replace(yes)

Actual Result:
InvalidOperationException is thrown Reconverting "Subgraph Operator" Node also duplicate node is created of the same Node

Expected Result:
Reconverting "Subgraph Operator" Node replaces existing node without throwing any exception

Reproducible in:
2020.1.0a6, 2019.3.0b4

Working fine on:
2019.3.0b3, 2019.3.0a10

Package version found: 7.1.2, 7.1.1

Package version working fine: 7.0.1, 7.0.0

NOTE:
Visual Effect Graph is introduced in 2019.3.0a10.

Environment:
Windows 10 & macOS 10.14

Stack Trace:
InvalidOperationException: Sequence contains no matching element
System.Linq.Enumerable.First[TSource] (System.Collections.Generic.IEnumerable`1[T] source, System.Func`2[T,TResult] predicate) (at <fbb5ed17eb6e46c680000f8910ebb50c>:0)
UnityEditor.VFX.UI.VFXConvertSubgraph+Context.TransferEdges () (at Library/PackageCache/com.unity.visualeffectgraph@7.1.2/Editor/GraphView/Views/VFXConvertSubgraph.cs:370)
UnityEditor.VFX.UI.VFXConvertSubgraph+Context.ConvertToSubgraphOperator (UnityEditor.VFX.UI.VFXView sourceView, System.Collections.Generic.IEnumerable`1[T] controllers, UnityEngine.Rect rect) (at Library/PackageCache/com.unity.visualeffectgraph@7.1.2/Editor/GraphView/Views/VFXConvertSubgraph.cs:238)
UnityEditor.VFX.UI.VFXConvertSubgraph.ConvertToSubgraphOperator (UnityEditor.VFX.UI.VFXView sourceView, System.Collections.Generic.IEnumerable`1[T] controllers, UnityEngine.Rect rect) (at Library/PackageCache/com.unity.visualeffectgraph@7.1.2/Editor/GraphView/Views/VFXConvertSubgraph.cs:26)
UnityEditor.VFX.UI.VFXView.ToSubgraphOperator (UnityEngine.UIElements.DropdownMenuAction a) (at Library/PackageCache/com.unity.visualeffectgraph@7.1.2/Editor/GraphView/Views/VFXView.cs:1756)
UnityEngine.UIElements.DropdownMenuAction.Execute () (at <afbdfd007ccb47e98566943b0715a4f7>:0)
UnityEditor.UIElements.EditorMenuExtensions+<>c__DisplayClass0_0.<PrepareMenu>b__0 () (at <52c46852ed4749ed926125cda2005635>:0)
UnityEditor.GenericMenu.CatchMenu (System.Object userData, System.String[] options, System.Int32 selected) (at <52c46852ed4749ed926125cda2005635>:0)