T-Mobile has released an update for the Samsung Galaxy S7 and S7 Edge on their network that is aimed at improving roaming on the devices. Build G930TUVU4BQH7 for the S7 and build G935TUVU4BQH7 for the S7 Edge are the updates you are looking for on these respective devices and they should be hitting your device over the course of the next few days.
The biggest change in this smallish 200MB update is improved IMS Roaming. What is IMS Roaming you ask? Essentially it is an interconnect between T-Mobile and other carriers to allow you to make VoLTE calls, video calls and media sessions to someone on another carrier in another country. It isn’t super sexy and unless you do international travel, it isn’t a big deal frankly. But it is good to see T-Mobile improving support for it (and Samsung for that matter).
The release notes for the update also indicates various system improvements have come to the Galaxy S7 and S7 Edge in these updates. What specifically was addressed is not outlined. What we do know is that the phones are still on Android Nougat 7.0 so no changes from that perspective.
T-Mobile has been phasing this rollout as they normally do so it could be several days before everyone sees the update.