Samsung has finally started pushing Android Pie 9.0 Stable update to Galaxy Note 9 along with the One UI. The OTA update is about 95MB and you can check the screenshot of the update which was taken by a user who previously participated in the beta program according to Gsmarena.
When Will Samsung Galaxy Note 9 Pie Update Receive Globally?
As of now we have come to know that the update is being rolled out in Germany, it might take a while when Samsung pushes the updates globally. The build number is N960FXXU2CRLT which comes out with the Android January security patch.