We have had the Lexus NX for a year and the sat nav has always chosen sensible routes. But a week ago it started taking us on completely pointless detours, going round in a circle and then back to the main route.

Today when on the road towards our house, with the destination set as our house, it told us to turn off in a completely different direction! There was no traffic or anything blocking the route.

Has anyone else encountered this problem? What can be done about it? I'd prefer not to have to spend time taking it back to the dealer.