PSA: Ipad owners cannot Restore iCloud backups from iPhones running iOS 12.1.2
Normally, a user is able to freely restore a backup made on an iPhone to an iPad, or vice versa, as both devices run the same operating system.
The iCloud system does not let a user restore an iCloud backup associated with an iOS version that is newer than the iOS version installed on the device.
If a user tries to restore a backup that is too new, the iOS setup screens are smart enough to guide the user through Software Update before continuing.
However, Apple has caused an issue for itself as the iOS releases for iPhone and iPad are out of sync. iPads can only update to iOS 12.1.1, whereas iPhones can update to iOS 12.1.2.