Fix the issue with the behaviour of Camera 3 after closing F9.

Author: mbm-OR

Source/RunActivity/Viewer3D/Cameras.cs

@@ -1083,6 +1083,21 @@ protected override void OnActivate(bool sameCamera)
                 isVisibleTrainCarViewerOrWebpage = (Viewer.TrainCarOperationsWindow.Visible && !Viewer.TrainCarOperationsViewerWindow.Visible) || Viewer.TrainCarOperationsViewerWindow.Visible || (Viewer.TrainCarOperationsWebpage?.Connections > 0 && Viewer.TrainCarOperationsWebpage.TrainCarSelected);
             }
 
+            if (isVisibleTrainCarViewerOrWebpage)
+            {
+                // Update the camera view
+                oldCarPosition = oldCarPosition == 0 && carPosition == 0 ? -1 : oldCarPosition;
+            }
+
+            if (attachedCar != null && !isVisibleTrainCarViewerOrWebpage && !Front)
+            {// Reset behaviour of camera 3, after closing F9-window and F9-web.
+                var attachedCarPosition = attachedCar.Train.Cars.TakeWhile(x => x.CarID != attachedCar.CarID).Count();
+                if (attachedCarPosition == carPosition)
+                {
+                    attachedCar = trainCars.Last();
+                }
+            }
+
             if (attachedCar == null || attachedCar.Train != Viewer.SelectedTrain || carPosition != oldCarPosition)
             {
                 if (Front)