[cupcakes aka dd]

So twice now I've travelled abroad to find only my text and calls work. My family all have iPhones two of them can use data and two cannot. We are all on the same plan. Getting a bit tired of this having to rely on hotel wifi. The one phone didn't allow data until a message popped up saying carrier has changed please update. Then that one worked. ???? I've read a network reset should solve it but I'm reluctant to try this in case it messes up something else whilst in another country