Note gets created after Users click 'Cancel'

Knowledge Article Number 000330081
Description
Starting in Summer ’15, Salesforce introduced Notes (Beta), an enhanced version of the Salesforce Notes functionality.  It's working as designed for the Note record to get created even after clicking on the cancel button.
Resolution
If new Notes is enabled, you will see the “New Note” button in the “Notes” related list.  The following is expected behavior:

Classic
1. Go to related list “Notes”. Click on “New Note” 
2. Note record is immediately created and saved.
3. Click Cancel button.
4. “Notes” will display record just created.

Lightning
1. Go to related list “Notes”. Click on “New” 
2. Enter a character in the subject or in the body.
3. Note record is immediately created and saved.
4. Click the 'X' button at the top-right of the note.
5. Notes related list will show a record has been created .


The cancel button in Salesforce Classic and the 'X' button in Lightning Experience will discard any changes made from clicking the “New Note” button. The new record though is created when you click on “New Note” button.  So if the New Note Button is clicked and nothing is entered and you click cancel, a blank note will be created.

If you need to remove the newly created record, please click the delete option from the “Notes” related list.