Tesla FSD visualization and calibration not matching

I just got my windshield replaced at Tesla service and after it calibrated FSD was off. It was hugging the right lane or even veering off into the next lane over on the right. What I found bizarre about all of this was that the FSD visualization actually accurately reflected the position of the car. It would show as hugging the right lane or crossing over into the next lane. Where is the Tesla FSD visualization coming from? And why is it not getting its sensory input from whatever is driving FSD? At any rate ate it is resolved now after I did another calibration. But I was curious why this phenomenon would happen