S9 loses service when not connected to the internet?

[Members_qYFjf63]

HI 

  My Mum uses an unlocked Galaxy S9 & a Sim only Sky contract. A few days ago she lost service but when she got home the mobile service returned. Now every time she leaves home the phone loses service? I have tried a number of things but to no avail, I have come to realise that she only has mobile service when the S9 is connected to the internet. The S9 connects automatically to her home internet network when she's at home & she gets service. When she's at work her phone automatically connects to her work internet & she gets mobile service. As soon as her S9 is not connected to the internet she loses all mobile service. Does anyone know what might be causing this & is there a solution.  Many thanks 

[Mitzzz999]

When she's on a WiFi connection her Internet based communication apps like emails and WhatsApp work yeah? But not when she's out and about... meaning that mobile data isn't working.

Does her calls and normal SMS work only when on a WiFi connection? Or do they not work at all...?

[antikythera]

Check how much credit is left on the SIM. She's not getting mobile service at all by the sounds of it but piggybacking off Wifi for apps as Mitzzz999 says. Also she may need to get in touch with Sky Mobile to sort any faulty SIM issues but make sure it is inserted properly before contacting them. If there's no signal on the mobile use yours or a landline (you will have to pay anyway for the call).