iMessage messages rant showing up
I just got a new iPhone at ATAT and they said they linked my old iPhone and my new iPhone together. All my apps are there but my recent messages rant showing up. My messages are from 2020 and it won't show me my most recent ones. I also keep getting the message " Messages in iCloud not available as iCloud and iMessage accounts do not match. How do I fix this?
iPhone 13 Pro, iOS 15