Recovery of Notes after update

It's not always the iOS update's fault!  Many things can cause phone problems.  If you tell people you think it's an iOS update, it might make it harder to fix or find a solution for the real issue.

Remember, the right question often leads to the solution!

Was/Is your device Jailbroken? If that's the situation, please be informed that attributing the issues to iOS updates may not be accurate.

iOS updates aim to enhance user experience, boost security, and fix bugs rather than disrupt core features. The majority of the issues after updates might stem from underlying, unmentioned factors. Updates won't typically alter personal data but may refine settings or features. Backup before major updates for safety. Review Apple's update details and backup advice for a smooth process.

Kindly consider checking your settings and addressing any device issues before attributing the issue to external factors. This could be a pure coincidence that the iOS update affected the iPhone functions.

Before initiating a standard iOS update, it's advisable to create a backup. Have you completed this step? If yes, proceed with the restoration from the backup.

See what each update does: OS — iOS 26, About iOS 18 Updates, About iOS 17 Updates, About iOS 16 Updates, About iOS 15 Updates, About iOS 14 Updates, About iOS 13 Updates, About iOS 12 Updates, and so on...

Neither iOS nor iCloud automatically delete your data due to low storage or iOS update. However, there are some nuances:

1. Local Device Storage (iPhone, iPad, Mac)
   1. When your device runs out of storage, iOS may stop adding new data, downloading apps, or updating existing apps.
   2. Some temporary files, cached data, and Safari website data may be automatically removed to free up space.
   3. If "Optimize Storage" is enabled for Photos or Music, full-resolution images or downloaded songs may be offloaded (but remain in iCloud).
2. iCloud Storage
   1. If your iCloud storage is full, new backups, photos, videos, and files may stop syncing.
   2. Existing files and backups are not deleted, but new iCloud backups might fail until storage is freed up.
   3. If you stop paying for extra iCloud storage and exceed the free 5GB limit, iCloud services may stop syncing, but no files are deleted immediately.
3. iCloud Drive & Third-Party Apps
   1. Some third-party apps that use iCloud (e.g., WhatsApp backups) might stop updating if iCloud is full.
   2. Apple does not delete files from iCloud Drive due to storage limits, but you won’t be able to add more files until you clear space.

Bottom Line:

No personal files (photos, documents, messages) get deleted automatically due to low storage, but system processes may offload, pause, or prevent new data from being saved.

Where were the Notes? The pic below is self-explanatory.