Fix spline model visibility after enable if was disabled on start

Source/Engine/Level/Actors/SplineModel.cpp

@@ -480,3 +480,11 @@ void SplineModel::OnTransformChanged()
 
     OnSplineUpdated();
 }
+
+void SplineModel::OnActiveInTreeChanged()
+{
+    // Base
+    ModelInstanceActor::OnActiveInTreeChanged();
+
+    OnSplineUpdated();
+}

Source/Engine/Level/Actors/SplineModel.h

@@ -125,4 +125,5 @@ protected:
 
     // [ModelInstanceActor]
     void OnTransformChanged() override;
+    void OnActiveInTreeChanged() override;
 };