His data is gone within a day or so and this month he’d been home the whole time and using WiFi. He went out today and I tried WhatsApping and texting him but neither message delivered. I could get through on a phone call though. I couldn’t find him on find my iPhone either when he was out. As soon as he came home again the messages all delivered and I can see him on find my iPhone. Does anyone know why or how to rectify this please?