There are two possible easy explanations:
Patriot is more capable than we thought, or
Kinzhal is less capable than claimed.
Maybe it is a bit of both.
Or third this is propaganda. Something the Ukrainians are good at. And the western press buys it without question.
Another possibility is launch pilot error.
The Kinzhal is supposed to be able to maneuver while enroute to the target.
To do this, the launch pilot would have to input interim waypoints into the Kinzhal.
This would complicate the Patriot’s ability to predict where the Kinzhal is flying to.
If the pilot only imputs the target’s GPS coordinates, it would not maneuver while enroute to the target.
The Patriot would easily calculate the flight path of the Kinzhal and launch a PAC-3 missile to intercept it.