This happened to me yesterday as well!
Exactly same place on the M25. Got off the motorway and tried turning the car off a couple of times but it was still frozen. Had to go old school and look at my road atlas and those big boards at the side of the road with arrows and place names on!
Once I had arrived at Farnborough i stopped at McDonald’s for a cheeky sausage and egg McMuffin and after 15 minutes resting the sat nav was fine.
Might still get it into Ford for a look and update if needed.