https://wccftech.com/xfinity-galaxy-s9-and-s9-android-pie-updates-rolling-out/

Samsung’s latest OneUI-based Android Pie update is rolling out in full force. Most international unlocked variants of the Galaxy S9, S9 Plus and Note 9 have received the updates. Carrier-locked devices in the US, however, are yet to receive the update. Today that changes as the Galaxy S9 Android Pie update seems to be finally rolling out to carrier-locked devices in the US. The Galaxy S9+ and S9+ on Comcast’s Xfinity network are getting the Pie update.

The update weighs in at a hefty 1.9GB and bears build number G960USQU3CSAB. It brings all the benefits of Android 9 Pie, One UI, and the January security patch in a single download. You can check if the update is available for your device from the Software update menu in the phone’s Settings app. The update will show up on its own at some point, but that can take some time, so it’s best to check on your own.