AT&T is shutting down its 3G network on Feb. 22, something that should only affect people with very old devices, mostly flip phones. But a subset of unlocked smartphone owners are getting caught up in this mess, and some of them don’t even know it.
The folks getting a nasty surprise are people who bought smartphones not designed for US networks. Some of them aren’t sold here, like Huawei and Xiaomi models. Those were always living on borrowed time. The really tricky ones, though, are Samsung models that look exactly like phones sold and supported in the US, but aren’t.