[Q] tab 3 sm-t211 stuck on cellular roaming topic

Hi, my dad is having a problem with his galaxy sm-t211 that I can't seem to find a fix for, I haven't even been able to find mention of it. His tab is unlocked. He is using his fido SIM chip with it. He gets data fine, but it is constantly in roaming mode. Even when I turn roaming off, it says that he has lost network connectivity because he is out of his home cellular network. Does anyone know if this issue is fixable. Maybe by flashing a modem for this region or something? Any and all help appreciated, thanks