The new update for Unlocked Galaxy Note 9 can be identified by firmware version  N960U1UEU8FUE1. The OTA package also improves Samsung’s Quick Share tool for seamless file sharing between Galaxy devices. Samsung recently detailed the June 2021 security patch, according to which it fixes 2 Critical, 27 High levels, and 5 Moderate levels Common Vulnerabilities and Exposures (CVE’s).  As always, the latest update is rolling out in batches. So, it may take a few days to reach your Unlocked Galaxy Note 9. You can manually check for the latest update on your Galaxy phones by navigating to Settings » Software updates. Samsung announced the Galaxy Note 9 back in August 2018 and soon it will become 3 years old. The smartphone received great software support from Samsung by receiving regular security patches and will continue to receive for a while. But, it won’t receive any further major OS upgrades. [source]

Unlocked Galaxy Note 9 receiving June 2021 security update in the US - 84