I have never lost my notes on any of my Iphones, but since 16.6.1 update, my yahoo notes have been significantly reduce to 16 from 212. I want to know why this happened, and if it was thoroughly tested before release. Apple needs to take responsibility and correct.
iPhone 11
Where were the Notes? See the pic below. You will get your answer
The various options that you are referring ("the second text menue") to will exist only if your Notes are on iCloud or the "On My Phone" Folder.
The 2 pics below are self-explanatory.
If you're missing notes on your iPhone, iPad, or iPod touch
Notes are always synced through Google, iCloud, AOL, Exchange, Outlook, Yahoo or any Other email Account
Any data on your device that isn't synced regularly will be stored in your iCloud Backup. With Backup turned on, iCloud takes periodic snapshots of this data to make sure it's easy to restore any time you get a new device. Between syncing and backing up, all of your data is kept safe in the cloud.
What does iCloud back up? - Apple Support (IN)
No disrespect, but you are speaking of this as if “the user” deleted the notes. That is incorrect. The update removed the notes. They were yahoo notes, they were not backed up. But Apple’s update removed them. How do we get them back?
Notes on Iphone 11 with 16.6.1 update
