Hi my wife's phone is Samsung m30s had a big problem she moved to New York and bought T-Mobile sim card and she can't get 4g or lte or 3g only she got 2g till now i don't understand why and how i bought brand name like Samsung and i got this problem
If you the phone dual sim try to move from sim 1 to sim 2 and then add the APN settings. If its not a dual sim card you will need to add the APN setttings for t mobile.
T mobile apn settings :
APN: epc.tmobile.com for 4G or LTE enabled devices, use this one instead: fast.tmobile.com instead
Proxy: <Leave in Blank>
Port: <Leave in Blank>
Username: <Leave in Blank>
Password: <Leave in Blank>
Server: <Leave in Blank>
APN type: default,supl,mms – for some samsung devices select internet+MMS, this is very important for you to be able to send and receive picture messages
APN Protocol: Leave it to the Default one
Let me know if that work for you.