Notes locked 🔒

If you don't know the password that the note was locked with, you will not be able to regain access to that locked note.

Resetting the notes password makes it so that you can lock/unlock new notes, it does not give you access to your old notes.

Using Touch ID to unlock your notes is a convenience, it does not mean that you can forget the password.

Similarly you can unlock your iPhone with Touch ID, but if you forget your iPhone passcode then you'll wind up needing to restore your phone. Again, because Touch ID does not replace your passwords or passcodes.

If you have changed the password, in connection with you forgetting the old one, then the Notes that were locked before you changed the code are still locked to the old code.

If you reset the password and create a new one - then only the future notes will get the new password.

See the reply to:

Forgot password for notes - Apple Community