Check you Notes folder in your email. To see the Notes folder, you must go to Settings >Mail,Contacts,Calendars > Email account > Toggle OFF Notes. Yes, OFF. Sounds backwards, but it works. You must have deleted the email address from in the Notes app. After recovering your notes, toggle notes off in all email accounts. Toggle Notes ON in iCloud. No more problems.
Sent from my ancient but trustworthy iPhone 5.