MDM transferred to new phone

My Dad got a new iPhone 17 and tried to set up from his old work phone (iPhone XR). He thought the mdm was disabled but it was not and now the iPhone 17 is stuck in start up on the mdm screen. He has retired and the new phone has nothing to do with his old company. We have tried restarting the phone to start the setup again but it keeps going back to the same screen.