iCloud backup is blocking AT&T data

New iPhoneX works with voice and data. However when I applied my iCloud backup to my phone the voice works but not the data. It’s on AT&T network. On my previous iPhone the data didn’t not work which prompted me into buying a new phone thinking it was a phone issue but it’s my iCloud that’s doing it. How do I fix this? My Apple ID is on 4 other devices with no issues.