Starting with version 1.4.1, the Wallet-as-a-Service Mobile app keeps each phone's MPC key material on that phone. The app no longer syncs it through iCloud Keychain to other devices signed in to the same Apple ID.
Each paired phone is a separate participant in its quorums, with its own identity. Previously, two phones that shared an Apple ID could end up with the same MPC identity, which could cause wallet creation to fail.
Phones that are already paired keep their existing key material when they update to version 1.4.1, and keep access to their quorums and wallets. No action is required.
To move signing to a new phone, add the new phone as a device, and then contact Ripple support to replace the old phone in its quorums. Self-service restructuring from the console supports Cloud quorums only. See Types of devices.