Thanks for your answer!
Does this mean that it is not possible to prepare a route in My Drive Web Route Planner, with multiple stops (or waypoints), and send it to the device, so it appears as a route in the device with 'my routes'?
Did you use an usb cable?
By the way, if you use the option 'Share' in MDW, while the route is open in Edit mode, you can also download it a .gpx. You wil then see that this .gpx consists two files: a route and a track.