@Montorsi-Paolo-0 This is your issue: you created the route based on OpenStreetMap. Instead, choose the Here or TomTom map. However, navigation always takes place based on the Here map. So, for creating your routes, it's better to use that map.
You can save the Here map as the default map by checking the box on the bottom line:
Last but not least: you need a gold subscription to do that!