Answer to: iPhone 6 shows 4G but no cellular dataI recently had a trip to Japan for which I switched my sims so I didn't get charged for using my phone abroad. When I returned to the US, I switched my sims back and I started to have this issue. While I was troubleshooting with the general settings I noticed that the Japanese sim had created a configuration profile for me. Once I deleted it everything went back to normal. Its missing on my phone now, but it should be under: Settings>General>Configuration Profile>Delete Profile Other Instructions to delete configuration profile from apple are in the link below: https://support.apple.com/en-us/HT205347 Hope this helps!