Be sure to delete those accounts from Duo Mobile on the old device or delete Duo Mobile entirely from the old device once you verify the passcodes generated by the restored accounts work for logging in to those services.
When you use the below methods to restore Duo accounts on a new or replacement device, be aware that: Duo Mobile's restore functionality lets you back up Duo-protected accounts and third-party OTP accounts (such as Google or Facebook) for recovery to the same device or to a new device.