How to reproduce:

1. Create a new VFX
2. Drag an edge from any block port while pressing alt key
3. Release alt key

Expected result: Exposed property is created

Actual result: Error is thrown to the console, edge sticks to cursor and exposed property is not created

No repro on 2023.2.0a5; Could be and issue from BBA;

ArgumentNullException: Value cannot be null.
Parameter name: source
System.Linq.Enumerable.OfType[TResult] (System.Collections.IEnumerable source) (at <06a41b943d5d41bf953a3d9839526e34>:0)
UnityEditor.VFX.UI.VFXDataAnchor.UnityEditor.Experimental.GraphView.IEdgeConnectorListener.OnDropOutsidePort (UnityEditor.Experimental.GraphView.Edge edge, UnityEngine.Vector2 position) (at /Users//Documents/unity/packages/com.unity.visualeffectgraph/Editor/GraphView/Elements/VFXDataAnchor.cs:311)