I recently swapped the sim from another iPhone to the another iPhone that had previous data on it, just signing off iCloud, etc. and resigning in to for iMessage, FaceTime, and other things. The phone is able to make calls, send and receive text. But it cannot receive calls. Whenever I try calling from my other phone, it just brings up a tone telling me to check number and try again. This is on AT&T. I did a sim swap from iPhone 6S to iPhone 6 Plus (cross upgrade/swap sim). The iPhone 6S came with a new sim and I activated online, and then I swapped the new activated sim to the old iPhone 6 Plus. I tried restarting phone, resetting network settings already. I do not want to backup and restore phone, rather not lose all the photos and music. Any idea why my new activated sim not working on the iPhone 6 Plus for receiving calls but can make outgoing calls and send and receive text?