sm-g928t no network imei is good

hi z3x team i fix this phone it work for two months and now no network it shows 4g signal but still no data please look at this for me Waiting ADB device… OK
Reading phone info…
Model: SM-G928T
Android version: 5.1.1
Product code: SM2G928TZKATMB
Phone version: G928TUVU2COJ5
PDA version: G928TUVU2COJ5
CSC version: G928TTMB2COJ5
CSC country code: USA
CSC sales code: TMB
HW version: REV1.0
Phone S/N: R58GB16WT2V
Modem board: SHANNON333
RF cal date: 20151112
Checking Super user right… true
Initializating zTool… OK
Running zTool, please wait… OK
Reading modem… OK
Patching modem… OK
Writing modem… OK
Rebooting phone… OK
Patching CERT check… done
Done with Samsung Tool PRO v.25.8