Steps to reproduce:

1. Open the attached package
2. Open VFX and subgraph operator windows
3. Make sure that VFX or any other window is focused and Subgraph operator tab is open but not visible/focused
4. Open Script, comment "//" next to Debug.log and save it
5. After domain reload, try to open subgraph operator again 

Actual results: second window of subgraph operator opens and errors are thrown

Expected results: When trying to open subgraph operator again it focuses existing subgraph operator window

Reproducible with versions: 2022.3 - 6000.3.0a5

Not reproducible with versions: 

Can’t test with versions: 

Tested on (OS): 

Notes:
{code:java}
Exception thrown while invoking [OnOpenAssetAttribute] method 'VisualEffectAssetEditor:OnOpenVFX (UnityEngine.EntityId,int)' : InvalidOperationException: Sequence contains more than one matching element
System.Linq.Enumerable.SingleOrDefault[TSource] (System.Collections.Generic.IEnumerable`1[T] source, System.Func`2[T,TResult] predicate) (at <175a161e03894f66a250f0632be3e461>:0)
UnityEditor.VFX.UI.VFXViewWindow.GetWindowLambda (System.Func`2[T,TResult] func, System.Boolean createIfNeeded, System.Boolean show) (at ./Library/PackageCache/com.unity.visualeffectgraph@162a3b265f04/Editor/GraphView/VFXViewWindow.cs:93) {code}
{code:java}
InvalidOperationException: Sequence contains more than one matching element
System.Linq.Enumerable.SingleOrDefault[TSource] (System.Collections.Generic.IEnumerable`1[T] source, System.Func`2[T,TResult] predicate) (at <175a161e03894f66a250f0632be3e461>:0)
UnityEditor.VFX.UI.VFXViewWindow.GetWindowLambda (System.Func`2[T,TResult] func, System.Boolean createIfNeeded, System.Boolean show) (at ./Library/PackageCache/com.unity.visualeffectgraph@162a3b265f04/Editor/GraphView/VFXViewWindow.cs:93) {code}