Update released by T-Mobile today for the Samsung Galaxy S9/S9+ includes security patch, bug fixes
The T-Mobile version of the Samsung Galaxy S9 and Samsung Galaxy S9+ are each receiving an OTA software update. The update for the Galaxy S9 carries software version G960USQU3ARG7, while the Galaxy S9+ update contains version G965USQU3ARG7. Both weigh in at 371.62MB, and feature the July 1, 2018 Android security update.
Besides updating the security patch on both models (albeit not to the latest available version), the new files include enhancements to the super slo-mo and AR Emoji features, and a Black screen fix. The update is rolling out to both models starting today.
When the notification arrives on your phone informing you that the update is ready to be installed, connect your device to a Wi-Fi signal and fully charge the battery to 50% or higher before starting the updating process. Since the update is arriving OTA, it will be sent out in waves. If you are the impatient type, you can try to manually update the phone by going to Settings > Software update > Download updates manually.