Been having this issues since day one and been fobbed off constanly .
I've been told :
Its the phone set up several times even the the phone has been set up lots of time either by message or manually
Its the sim so got sent another sim
Its because the phone needs setting as bew sim
Its my local mast being repaired even though it happens at working 30 mile away from were i live.
Its the phone set up again
So ive bought a new phone and guess what still faults.
My colleagues phone does the same at the moment the mobile data seems off as much as its on