[Update November 15, 2018: Sprint is also rolling out the November 2018 security patch for the Galaxy Note 9 and Galaxy Note 8. The update has the same software versions and changelog. For more read below.]
The latest software update includes the November 2018 security patch, minor bug fixes, and minor improvements.
To identify the updates, here are the software versions. The Galaxy Note 9 is carrying version N960USQS1ARJ9, while the Galaxy Note 8 has version N950USQS5CRJ3.
If you are still waiting for the update to ping on your Galaxy Note device, you can check for it manually by heading into Settings > Software Updates or simply wait for it.