When restoring a backup, taken while enrolled in MDM vendor A and restoring it on the same device but attempting to enroll in Intune, this will result in failure.However, in a migration scenario where you are moving from one MDM vendor to another, it is important to be aware of. In most cases, your MDM enrollment state (at the time of backup) isn't of any special significance.Migrating to MEM/Intune from another EMM vendor Specific to backup/restore Alternatively, if you cannot ensure that the device was unenrolled when the backup was taken, consider hiding the ‘restore’ setup assistant screen in your iOS/iPadOS enrollment profile in the Microsoft Endpoint Manager console. To facilitate this type of migration, one option would be to retire the device from the prior EMM before the user does a backup of the iOS/iPadOS device. If the management profile was locked on the device by the prior EMM, the end user won't have an option to remove the management profile on the device. To avoid issues, ensure that users do not perform a backup whilst the device is enrolled – you want users to perform any backup/restore activities without impacting the management profile and related certificates.Is the management certificate being restored still valid? Was the management certificate renewed after the backup was done? These scenarios might be less common, but they are worth being aware of – especially if the backup being restored isn't recent. What about the Azure AD record? What about the management certificate? These certificates are valid for a year for iOS/iPadOS. For example, has the corresponding device record in Intune been deleted? (either by accident or an intentional retirement/clean-up). Also consider the amount of time that has elapsed since the backup was taken, and what impact a restore (which essentially sets the device back to that prior time), might have.As a result, post-restore, the device will need to be re-enrolled using the Company Portal app before it will be functional. If you performed a remote wipe by using the MEM/Intune web portal, this will first unenroll the device before the wipe.If you performed a local reset of the device, then the device will remain enrolled post-restore and shouldn't require any intervention.In addition, specific to Intune, there are two different methods to reset a device and they will affect the post-restore behavior regarding enrollment state:.This result is typically a good thing, unless this process is being performed as part of a migration to a different EMM vendor (see below). You retain the management state (and management profile) that you had at the time the backup was done.
The result is that you don't go through any 'remote management' and subsequent enrollment steps.
For details refer to the following Apple support document.
Cloud mobile phone won t turn on.Device-to-Device migration as offered on the Quick Start screen after resetting an iOS device isn't supported with Apple Business Manager (ABM).