"The Loops" Route Derails Cars When Continuing a Session.

When I operate "The Loops" I have problems with cars randomly derailing when returning to the route. This does not happen while I am operating, but after I save. When I return, to continue, cars are randomly derailed. This makes it impossible to use this route. I have tried it with derail mode set to no derailments, and they still derail. Is there anything that can be done about this? This has not been a problem with other routes.

Thank You