https://wccftech.com/android-pie-update-rolling-out-for-the-us-unlocked-galaxy-note-9/

It’s hard owing a carrier-unlocked Samsung device in the US. Yes, you get a carrier-specific bloatware-free device that you can use with any provider, but you’re almost always a few weeks behind in terms of major (and even minor) software upgrades. All variants of the Galaxy Note 9 have long received their Android Pie update except for the carrier-unlocked ones. Today, Samsung has started rolling out the latest iteration of Android to unlocked models of its flagship phablet in the United States.

Multiple users in the US have reported that the Android Pie update is finally rolling out in the country. It bears firmware version N960U1UEUCSB3 and is rolling out over-the-air. The update weighs just under 1.7GB and brings the February 2019 security patch. All of the features that are part and parcel of Android Pie are included in this major update. That’s in addition to One UI, which is Samsung’s new user interface for its devices. OneUI brings forth a lot of changes in the form of UI changes for several system apps, a system-wide dark mode and more