Really "instantly"?
I've owned dozens of automobiles with exterior temperature indicators from GM, Ford, Honda, and Mazda and there has been some delay on all of them. Every model has different logic, but it typically takes several miles of driving while the vehicle is moving over a certain speed before the indicated temperature starts slowly changing. The indicated temperature usually matches the actual temperature after moving for a few to several miles. This is done because the OAT sensor in an automobile is typically in the front near hot components and inches above the road surface - the vehicle needs to be moving to get a reasonably accurate read that is not affected by heat generated by the vehicle.
With that said, my '23 Model Y's exterior temperature indication is very slow to respond - much slower than any other automobile I've ever owned.