AppleInsider and other foreign media reported that some iCloud users are reporting syncing problems with iCloud Drive, uploading photos and backups after the iOS 16.3 update.
According to reports on the Apple Support forums and Reddit, after updating to iOS 16.3, moving the iCloud Backup slider to On causes an error. While the problem seems to be high for users who do not have iCloud 2-Step Verification enabled, cases have also been reported by users who have enabled 2-Step Verification.
Foreign media believe that this iCloud error is related to the iOS 16.3 update. The iOS 16.3 update expands iCloud Advanced Data Protection outside the US and adds support for a physical security key for Apple ID.
According to MacRumors, Apple will release a minor update to iOS 16.3.1 sometime this month. The iOS 16.3.1 update will reportedly focus on fixing bugs reported in the iOS 16.3 update.