I am currently on a trip in Bucharest, Romania. I have had very inconsistent connections on my iPhone 6 for data but rock solid connections on my wife's iPhone 5s. Both are running iOS 9.3.5. We are on the Simple Choice plan which is supposed to give us unlimited international roaming at 2G speeds (128 kbps). The customer support people have been nice but not able to resolve the problem. They granted me a 24-hour high-speed data pass, which has now enabled my iPhone 6 to have a solid data connection, but this is not a sustainable solution. My guess is this is a link level (L1 or L2) failure at the tower near where we're staying that is preventing the 2G connectivity from being reliable. I suspect that the local partner carriers (Orange, Telekom.ro, Vodaphone) are not very concerned about providing reliable 2G service to T-Mobile USA's customers. I have tried all the usual troubleshooting on my phone and nothing has helped other than the high speed data pass, which I am not willing to pay extra $$$ for. Has anyone had a similar experience?