Hi, i had a data issue yesterday on an iPhone 8 where by it wouldn't connect to the internet either through data or WiFi. I tried fixing it by factoring resetting the phone. It work for a while but the same problem occurred again had to change to another phone. Still i faced the same issue on the second mobile which was an iPhone 7.
No cellular data and cannot connect to WiFi.
Note that this is not really a developer's question. Nevertheless… Do you get 4G signal ? Can you call from the phone ?. Have you checked it is not a network operator issue (as it occurs on both phones, problem is probably no to look in the phones).