My iCloud backup, with years of data, including apps which only had local storage, was completely borked when I upgraded to iOS 13 (on my iPhone XS). My phone would enter a boot loop during the iCloud restore process, and I tried 15 different restores (different iOS 13 versions including beta versions, iTunes backups, a couple different types of restores they have at the Genius Bar, a direct phone-to-phone restore, c…
I feel your pain. I hope you remember in the future:
Unless a backup can be verified, it is not a backup.
Backing up to a complex or binary format is trouble.