Galaxy Note9 users are reporting that they are getting an OTA update on their devices but interestingly, the firmware version N960FXXS2ARH6 is only available in the Baltic region, Romania, Slovakia, Luxembourg and Bulgaria.
The OTA update isn't anything special, but it does fix some vulnerabilities with the latest September security patch. These include nine critical security issues and 18 additional ones for Samsung Vulnerabilities and Exposures (SVE) items.
Тhe changelog also mentions stability improvements and bug fixes along with new features, but given the size of the patch (72MB), we doubt it has anything major.
You can try and check for the update manually or connect via VPN from one of the countries listed above.