Do us all a favour and open the session in Surveyor. Select the "Tracks" tab (F4 function key) and then "Trackside mode" (Y key) then click the "properties" button ( the question mark (?)).
Now click on one of the switch levers that is giving trouble, and look at the layer name (top right-hand side of the properties window). If it is showing as being on a session layer then that is the cause of the issue.
What you do about it is up to you, but the levers should be on a route layer to avoid problems with resuming a saved game.