In the first week of 2017 AT&T has discontinued its 2G service in the USA.
Customers with roaming SIM cards supplied by the Button Corporation may have had devices getting disconnected if they have been using AT&T network.
To scan and join T-mobile 2G network, proceed as follows:
1) Power bttn off
2) Press and hold bttn down
3) Power on, and wait until you see blue lights appear and then release bttn
4) Wait until you see one or more solid blue lights, indicating signal level.
5) After signal has been acquired, press the bttn for 6 seconds.
bttn will then automatically join the T-mobile 2G network. If you encounter issues, please create a support ticket.