Q: iCloud

From my own testing, it seems to depend on how you delete the note...

If you delete the note on iCloud.com:

• You can easily recover the note by going to the Trash folder.

If you delete the note on an iOS device:

• You can recover the note by restoring the device (if it's been backed up).
• You can recover the note from a device that hasn't recieved the latest sync changes.

See this -- iCloud: Restore or set up your iOS device from iCloud

In Notes, do you see a Recently deleted folder?

Your next step would be to reach out to Apple Support (link at bottom of the page).