Strasbourg

Has anyone experienced this problem? Our 18 registered petrol Kodiak DSG with all the bells and whistles has been excellent up to now. The local Speed Limit readout has become inaccurate on a number of important roads. Reading 60mph when it is 40mph. Local dealer unable to correct this fault which it said has occured on a new Karok. They did not say how that was resolved pointing out that this data is provided by third party, which I believe is "Here", the consortium of European car manufacturers Sat Nav data provider. Eager to find a solution without changing brand.