Samsung first released the One UI 2.5 update to the unlocked variants of the Galaxy S9 series and the Galaxy Note 9 last month. The company is now releasing the same update to carrier variants of the smartphones in the US and other markets. T-Mobile's versions of the Galaxy S9 and the Galaxy Note 9 have started receiving the One UI 2.5 and a new security patch.
The Galaxy S9, Galaxy S9+, and the Galaxy Note 9 on T-Mobile's network in the US have started getting the One UI 2.5 update and the October 2020 security patch. The new software updates carry firmware versions G960USQU8FTJ3, G965USQU8FTJ3, and N960USQU5FTJ3 for the Galaxy S9, Galaxy S9+, and the Galaxy Note 9, respectively.
If you are a Galaxy S9, Galaxy S9+, or Galaxy Note 9 user on T-Mobile's network, you can check for the One UI 2.5 update by tapping the Download and install option inside the phone’s Settings » Software update menu. This is possibly the last big software update for the Galaxy S9, Galaxy S9, and the Galaxy Note 9.
The official changelog on T-Mobile's website only mentions the new security patch, One UI 2.5, and additional updates and improvements. However, we know that the One UI 2.5 update brings new features, including Wireless DeX and an improved keyboard with integrated YouTube search and a split layout to the phones.
The new software also brings adjustable recording duration for the Single Take mode in the camera app. Video recording resolution can be selected in the Pro Mode, and the Messages app can send SOS messages every 30 seconds. You can read all the details about the October 2020 security patch here.